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2025-07-29fortify: Fix incorrect reporting of read buffer sizeKees Cook1-1/+1
When FORTIFY_SOURCE reports about a run-time buffer overread, the wrong buffer size was being shown in the error message. (The bounds checking was correct.) Fixes: 3d965b33e40d ("fortify: Improve buffer overflow reporting") Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/20250729231817.work.023-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-29kstack_erase: Fix missed export of renamed KSTACK_ERASE_CFLAGSKees Cook1-1/+1
Certain targets disable kstack_erase by filtering out KSTACK_ERASE_CFLAGS rather than adding DISABLE_KSTACK_ERASE. The renaming to kstack_erase missed the CFLAGS export, which broke those build targets (e.g. x86 vdso32). Fixes: 76261fc7d1be ("stackleak: Split KSTACK_ERASE_CFLAGS from GCC_PLUGINS_CFLAGS") Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-28staging: media: atomisp: Fix stack buffer overflow in gmin_get_var_int()Kees Cook1-4/+5
When gmin_get_config_var() calls efi.get_variable() and the EFI variable is larger than the expected buffer size, two behaviors combine to create a stack buffer overflow: 1. gmin_get_config_var() does not return the proper error code when efi.get_variable() fails. It returns the stale 'ret' value from earlier operations instead of indicating the EFI failure. 2. When efi.get_variable() returns EFI_BUFFER_TOO_SMALL, it updates *out_len to the required buffer size but writes no data to the output buffer. However, due to bug #1, gmin_get_var_int() believes the call succeeded. The caller gmin_get_var_int() then performs: - Allocates val[CFG_VAR_NAME_MAX + 1] (65 bytes) on stack - Calls gmin_get_config_var(dev, is_gmin, var, val, &len) with len=64 - If EFI variable is >64 bytes, efi.get_variable() sets len=required_size - Due to bug #1, thinks call succeeded with len=required_size - Executes val[len] = 0, writing past end of 65-byte stack buffer This creates a stack buffer overflow when EFI variables are larger than 64 bytes. Since EFI variables can be controlled by firmware or system configuration, this could potentially be exploited for code execution. Fix the bug by returning proper error codes from gmin_get_config_var() based on EFI status instead of stale 'ret' value. The gmin_get_var_int() function is called during device initialization for camera sensor configuration on Intel Bay Trail and Cherry Trail platforms using the atomisp camera stack. Reported-by: zepta <z3ptaa@gmail.com> Closes: https://lore.kernel.org/all/CAPBS6KoQyM7FMdPwOuXteXsOe44X4H3F8Fw+y_qWq6E+OdmxQA@mail.gmail.com Fixes: 38d4f74bc148 ("media: atomisp_gmin_platform: stop abusing efivar API") Reviewed-by: Hans de Goede <hansg@kernel.org> Link: https://lore.kernel.org/r/20250724080756.work.741-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-26sched/task_stack: Add missing const qualifier to end_of_stack()Kees Cook1-1/+1
Add missing const qualifier to the non-CONFIG_THREAD_INFO_IN_TASK version of end_of_stack() to match the CONFIG_THREAD_INFO_IN_TASK version. Fixes a warning with CONFIG_KSTACK_ERASE=y on archs that don't select THREAD_INFO_IN_TASK (such as LoongArch): error: passing 'const struct task_struct *' to parameter of type 'struct task_struct *' discards qualifiers The stackleak_task_low_bound() function correctly uses a const task parameter, but the legacy end_of_stack() prototype didn't like that. Build tested on loongarch (with CONFIG_KSTACK_ERASE=y) and m68k (with CONFIG_DEBUG_STACK_USAGE=y). Fixes: a45728fd4120 ("LoongArch: Enable HAVE_ARCH_STACKLEAK") Reported-by: Nathan Chancellor <nathan@kernel.org> Closes: https://lore.kernel.org/all/20250726004313.GA3650901@ax162 Cc: Youling Tang <tangyouling@kylinos.cn> Cc: Huacai Chen <chenhuacai@loongson.cn> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-26kstack_erase: Support Clang stack depth trackingKees Cook2-1/+10
Wire up CONFIG_KSTACK_ERASE to Clang 21's new stack depth tracking callback[1] option. Link: https://clang.llvm.org/docs/SanitizerCoverage.html#tracing-stack-depth [1] Acked-by: Nicolas Schier <n.schier@avm.de> Link: https://lore.kernel.org/r/20250724055029.3623499-4-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-26kstack_erase: Add -mgeneral-regs-only to silence Clang warningsKees Cook1-0/+1
Once CONFIG_KSTACK_ERASE is enabled with Clang on i386, the build warns: kernel/kstack_erase.c:168:2: warning: function with attribute 'no_caller_saved_registers' should only call a function with attribute 'no_caller_saved_registers' or be compiled with '-mgeneral-regs-only' [-Wexcessive-regsave] Add -mgeneral-regs-only for the kstack_erase handler, to make Clang feel better (it is effectively a no-op flag for the kernel). No binary changes encountered. Build & boot tested with Clang 21 on x86_64, and i386. Build tested with GCC 14.2.0 on x86_64, i386, arm64, and arm. Reported-by: Nathan Chancellor <nathan@kernel.org> Closes: https://lore.kernel.org/all/20250726004313.GA3650901@ax162 Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-26init.h: Disable sanitizer coverage for __init and __headKees Cook2-2/+4
While __noinstr already contained __no_sanitize_coverage, it needs to be added to __init and __head section markings to support the Clang implementation of CONFIG_KSTACK_ERASE. This is to make sure the stack depth tracking callback is not executed in unsupported contexts. The other sanitizer coverage options (trace-pc and trace-cmp) aren't needed in __head nor __init either ("We are interested in code coverage as a function of a syscall inputs"[1]), so this is fine to disable for them as well. Link: https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/kernel/kcov.c?h=v6.14#n179 [1] Acked-by: Marco Elver <elver@google.com> Link: https://lore.kernel.org/r/20250724055029.3623499-3-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-26kstack_erase: Disable kstack_erase for all of arm compressed boot codeKees Cook1-1/+1
When building with CONFIG_KSTACK_ERASE=y and CONFIG_ARM_ATAG_DTB_COMPAT=y, the compressed boot environment encounters an undefined symbol error: ld.lld: error: undefined symbol: __sanitizer_cov_stack_depth >>> referenced by atags_to_fdt.c:135 This occurs because the compiler instruments the atags_to_fdt() function with sanitizer coverage calls, but the minimal compressed boot environment lacks access to sanitizer runtime support. The compressed boot environment already disables stack protector with -fno-stack-protector. Similarly disable sanitizer coverage by adding $(DISABLE_KSTACK_ERASE) to the general compiler flags (and remove it from the one place it was noticed before), which contains the appropriate flags to prevent sanitizer instrumentation. This follows the same pattern used in other early boot contexts where sanitizer runtime support is unavailable. Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Closes: https://lore.kernel.org/all/CA+G9fYtBk8qnpWvoaFwymCx5s5i-5KXtPGpmf=_+UKJddCOnLA@mail.gmail.com Reported-by: Nathan Chancellor <nathan@kernel.org> Closes: https://lore.kernel.org/all/20250726004313.GA3650901@ax162 Suggested-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-24x86: Handle KCOV __init vs inline mismatchesKees Cook10-13/+13
GCC appears to have kind of fragile inlining heuristics, in the sense that it can change whether or not it inlines something based on optimizations. It looks like the kcov instrumentation being added (or in this case, removed) from a function changes the optimization results, and some functions marked "inline" are _not_ inlined. In that case, we end up with __init code calling a function not marked __init, and we get the build warnings I'm trying to eliminate in the coming patch that adds __no_sanitize_coverage to __init functions: WARNING: modpost: vmlinux: section mismatch in reference: xbc_exit+0x8 (section: .text.unlikely) -> _xbc_exit (section: .init.text) WARNING: modpost: vmlinux: section mismatch in reference: real_mode_size_needed+0x15 (section: .text.unlikely) -> real_mode_blob_end (section: .init.data) WARNING: modpost: vmlinux: section mismatch in reference: __set_percpu_decrypted+0x16 (section: .text.unlikely) -> early_set_memory_decrypted (section: .init.text) WARNING: modpost: vmlinux: section mismatch in reference: memblock_alloc_from+0x26 (section: .text.unlikely) -> memblock_alloc_try_nid (section: .init.text) WARNING: modpost: vmlinux: section mismatch in reference: acpi_arch_set_root_pointer+0xc (section: .text.unlikely) -> x86_init (section: .init.data) WARNING: modpost: vmlinux: section mismatch in reference: acpi_arch_get_root_pointer+0x8 (section: .text.unlikely) -> x86_init (section: .init.data) WARNING: modpost: vmlinux: section mismatch in reference: efi_config_table_is_usable+0x16 (section: .text.unlikely) -> xen_efi_config_table_is_usable (section: .init.text) This problem is somewhat fragile (though using either __always_inline or __init will deterministically solve it), but we've tripped over this before with GCC and the solution has usually been to just use __always_inline and move on. For x86 this means forcing several functions to be inline with __always_inline. Link: https://lore.kernel.org/r/20250724055029.3623499-2-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-24arm64: Handle KCOV __init vs inline mismatchesKees Cook1-1/+1
GCC appears to have kind of fragile inlining heuristics, in the sense that it can change whether or not it inlines something based on optimizations. It looks like the kcov instrumentation being added (or in this case, removed) from a function changes the optimization results, and some functions marked "inline" are _not_ inlined. In that case, we end up with __init code calling a function not marked __init, and we get the build warnings I'm trying to eliminate in the coming patch that adds __no_sanitize_coverage to __init functions: WARNING: modpost: vmlinux: section mismatch in reference: acpi_get_enable_method+0x1c (section: .text.unlikely) -> acpi_psci_present (section: .init.text) This problem is somewhat fragile (though using either __always_inline or __init will deterministically solve it), but we've tripped over this before with GCC and the solution has usually been to just use __always_inline and move on. For arm64 this requires forcing one ACPI function to be inlined with __always_inline. Link: https://lore.kernel.org/r/20250724055029.3623499-1-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-21s390: Handle KCOV __init vs inline mismatchesKees Cook3-3/+3
When KCOV is enabled all functions get instrumented, unless the __no_sanitize_coverage attribute is used. To prepare for __no_sanitize_coverage being applied to __init functions, we have to handle differences in how GCC's inline optimizations get resolved. For s390 this exposed a place where the __init annotation was missing but ended up being "accidentally correct". Fix this cases and force a couple functions to be inline with __always_inline. Acked-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20250717232519.2984886-7-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-21arm: Handle KCOV __init vs inline mismatchesKees Cook5-5/+5
When KCOV is enabled all functions get instrumented, unless the __no_sanitize_coverage attribute is used. To prepare for __no_sanitize_coverage being applied to __init functions, we have to handle differences in how GCC's inline optimizations get resolved. For arm this exposed several places where __init annotations were missing but ended up being "accidentally correct". Fix these cases and force several functions to be inline with __always_inline. Acked-by: Nishanth Menon <nm@ti.com> Acked-by: Lee Jones <lee@kernel.org> Reviewed-by: Nishanth Menon <nm@ti.com> Link: https://lore.kernel.org/r/20250717232519.2984886-5-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-21mips: Handle KCOV __init vs inline mismatchKees Cook1-1/+1
When KCOV is enabled all functions get instrumented, unless the __no_sanitize_coverage attribute is used. To prepare for __no_sanitize_coverage being applied to __init functions, we have to handle differences in how GCC's inline optimizations get resolved. For mips this requires adding the __init annotation on init_mips_clocksource(). Reviewed-by: Huacai Chen <chenhuacai@loongson.cn> Link: https://lore.kernel.org/r/20250717232519.2984886-9-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-21powerpc/mm/book3s64: Move kfence and debug_pagealloc related calls to __init sectionRitesh Harjani (IBM)2-5/+5
Move a few kfence and debug_pagealloc related functions in hash_utils.c and radix_pgtable.c to __init sections since these are only invoked once by an __init function during system initialization. i.e. - hash_debug_pagealloc_alloc_slots() - hash_kfence_alloc_pool() - hash_kfence_map_pool() The above 3 functions only gets called by __init htab_initialize(). - alloc_kfence_pool() - map_kfence_pool() The above 2 functions only gets called by __init radix_init_pgtable() This should also help fix warning msgs like: >> WARNING: modpost: vmlinux: section mismatch in reference: hash_debug_pagealloc_alloc_slots+0xb0 (section: .text) -> memblock_alloc_try_nid (section: .init.text) Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202504190552.mnFGs5sj-lkp@intel.com/ Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Link: https://lore.kernel.org/r/20250717232519.2984886-8-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-21configs/hardening: Enable CONFIG_INIT_ON_FREE_DEFAULT_ONKees Cook1-0/+3
To reduce stale data lifetimes, enable CONFIG_INIT_ON_FREE_DEFAULT_ON as well. This matches the addition of CONFIG_STACKLEAK=y, which is doing similar for stack memory. Link: https://lore.kernel.org/r/20250717232519.2984886-13-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-21configs/hardening: Enable CONFIG_KSTACK_ERASEKees Cook1-0/+3
Since we can wipe the stack with both Clang and GCC plugins, enable this for the "hardening.config" for wider testing. Link: https://lore.kernel.org/r/20250717232519.2984886-12-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-21stackleak: Split KSTACK_ERASE_CFLAGS from GCC_PLUGINS_CFLAGSKees Cook8-18/+27
In preparation for Clang stack depth tracking for KSTACK_ERASE, split the stackleak-specific cflags out of GCC_PLUGINS_CFLAGS into KSTACK_ERASE_CFLAGS. Link: https://lore.kernel.org/r/20250717232519.2984886-3-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-21stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depthKees Cook5-32/+32
The Clang stack depth tracking implementation has a fixed name for the stack depth tracking callback, "__sanitizer_cov_stack_depth", so rename the GCC plugin function to match since the plugin has no external dependencies on naming. Link: https://lore.kernel.org/r/20250717232519.2984886-2-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-21stackleak: Rename STACKLEAK to KSTACK_ERASEKees Cook37-95/+101
In preparation for adding Clang sanitizer coverage stack depth tracking that can support stack depth callbacks: - Add the new top-level CONFIG_KSTACK_ERASE option which will be implemented either with the stackleak GCC plugin, or with the Clang stack depth callback support. - Rename CONFIG_GCC_PLUGIN_STACKLEAK as needed to CONFIG_KSTACK_ERASE, but keep it for anything specific to the GCC plugin itself. - Rename all exposed "STACKLEAK" names and files to "KSTACK_ERASE" (named for what it does rather than what it protects against), but leave as many of the internals alone as possible to avoid even more churn. While here, also split "prev_lowest_stack" into CONFIG_KSTACK_ERASE_METRICS, since that's the only place it is referenced from. Suggested-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250717232519.2984886-1-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-19seq_buf: Introduce KUnit testsKees Cook3-0/+218
Add KUnit tests for the seq_buf API to ensure its correctness and prevent future regressions, covering the following functions: - seq_buf_init() - DECLARE_SEQ_BUF() - seq_buf_clear() - seq_buf_puts() - seq_buf_putc() - seq_buf_printf() - seq_buf_get_buf() - seq_buf_commit() $ tools/testing/kunit/kunit.py run seq_buf =================== seq_buf (9 subtests) =================== [PASSED] seq_buf_init_test [PASSED] seq_buf_declare_test [PASSED] seq_buf_clear_test [PASSED] seq_buf_puts_test [PASSED] seq_buf_puts_overflow_test [PASSED] seq_buf_putc_test [PASSED] seq_buf_printf_test [PASSED] seq_buf_printf_overflow_test [PASSED] seq_buf_get_buf_commit_test ===================== [PASSED] seq_buf ===================== Link: https://lore.kernel.org/r/20250717085156.work.363-kees@kernel.org Reviewed-by: David Gow <davidgow@google.com> Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-17string: Group str_has_prefix() and strstarts()Andy Shevchenko1-10/+10
The two str_has_prefix() and strstarts() are about the same with a slight difference on what they return. Group them in the header. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20250711085514.1294428-1-andriy.shevchenko@linux.intel.com Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-14kunit/fortify: Add back "volatile" for sizeof() constantsKees Cook1-2/+2
It seems the Clang can see through OPTIMIZER_HIDE_VAR when the constant is coming from sizeof. Adding "volatile" back to these variables solves this false positive without reintroducing the issues that originally led to switching to OPTIMIZER_HIDE_VAR in the first place[1]. Reported-by: Nathan Chancellor <nathan@kernel.org> Closes: https://github.com/ClangBuiltLinux/linux/issues/2075 [1] Cc: Jannik Glückert <jannik.glueckert@gmail.com> Suggested-by: Nathan Chancellor <nathan@kernel.org> Fixes: 6ee149f61bcc ("kunit/fortify: Replace "volatile" with OPTIMIZER_HIDE_VAR()") Reviewed-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20250628234034.work.800-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-06-27acpi: nfit: intel: avoid multiple -Wflex-array-member-not-at-end warningsGustavo A. R. Silva1-67/+52
-Wflex-array-member-not-at-end was introduced in GCC-14, and we are getting ready to enable it, globally. Use the new TRAILING_OVERLAP() helper to fix a dozen instances of the following type of warning: drivers/acpi/nfit/intel.c:692:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] Acked-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/aF7pF4kej8VQapyR@kspp Signed-off-by: Kees Cook <kees@kernel.org>
2025-06-18stddef: Introduce TRAILING_OVERLAP() helper macroGustavo A. R. Silva1-0/+20
Add new TRAILING_OVERLAP() helper macro to create a union between a flexible-array member (FAM) and a set of members that would otherwise follow it. This overlays the trailing members onto the FAM while preserving the original memory layout. Co-developed-by: Kees Cook <kees@kernel.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/aFG8gEwKXAWWIvX0@kspp Signed-off-by: Kees Cook <kees@kernel.org>
2025-06-18mux: Convert mux_control_ops to a flex array member in mux_chipThorsten Blum2-6/+5
Convert mux_control_ops to a flexible array member at the end of the mux_chip struct and add the __counted_by() compiler attribute to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE. Use struct_size() to calculate the number of bytes to allocate for a new mux chip and to remove the following Coccinelle/coccicheck warning: WARNING: Use struct_size Use size_add() to safely add any extra bytes. No functional changes intended. Link: https://github.com/KSPP/linux/issues/83 Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Link: https://lore.kernel.org/r/20250610104106.1948-2-thorsten.blum@linux.dev Signed-off-by: Kees Cook <kees@kernel.org>
2025-06-15Linux 6.16-rc2Linus Torvalds1-1/+1
2025-06-16gendwarfksyms: Fix structure type overridesSami Tolvanen2-58/+21
As we always iterate through the entire die_map when expanding type strings, recursively processing referenced types in type_expand_child() is not actually necessary. Furthermore, the type_string kABI rule added in commit c9083467f7b9 ("gendwarfksyms: Add a kABI rule to override type strings") can fail to override type strings for structures due to a missing kabi_get_type_string() check in this function. Fix the issue by dropping the unnecessary recursion and moving the override check to type_expand(). Note that symbol versions are otherwise unchanged with this patch. Fixes: c9083467f7b9 ("gendwarfksyms: Add a kABI rule to override type strings") Reported-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-06-16kbuild: move warnings about linux/export.h from W=1 to W=2Masahiro Yamada2-6/+12
This hides excessive warnings, as nobody builds with W=2. Fixes: a934a57a42f6 ("scripts/misc-check: check missing #include <linux/export.h> when W=1") Fixes: 7d95680d64ac ("scripts/misc-check: check unnecessary #include <linux/export.h> when W=1") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com>
2025-06-13io_uring: run local task_work from ring exit IOPOLL reapingJens Axboe1-0/+3
In preparation for needing to shift NVMe passthrough to always use task_work for polled IO completions, ensure that those are suitably run at exit time. See commit: 9ce6c9875f3e ("nvme: always punt polled uring_cmd end_io work to task_work") for details on why that is necessary. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-06-13nvme: always punt polled uring_cmd end_io work to task_workJens Axboe1-14/+7
Currently NVMe uring_cmd completions will complete locally, if they are polled. This is done because those completions are always invoked from task context. And while that is true, there's no guarantee that it's invoked under the right ring context, or even task. If someone does NVMe passthrough via multiple threads and with a limited number of poll queues, then ringA may find completions from ringB. For that case, completing the request may not be sound. Always just punt the passthrough completions via task_work, which will redirect the completion, if needed. Cc: stable@vger.kernel.org Fixes: 585079b6e425 ("nvme: wire up async polling for io passthrough commands") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-06-13posix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del()Oleg Nesterov1-0/+9
If an exiting non-autoreaping task has already passed exit_notify() and calls handle_posix_cpu_timers() from IRQ, it can be reaped by its parent or debugger right after unlock_task_sighand(). If a concurrent posix_cpu_timer_del() runs at that moment, it won't be able to detect timer->it.cpu.firing != 0: cpu_timer_task_rcu() and/or lock_task_sighand() will fail. Add the tsk->exit_state check into run_posix_cpu_timers() to fix this. This fix is not needed if CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y, because exit_task_work() is called before exit_notify(). But the check still makes sense, task_work_add(&tsk->posix_cputimers_work.work) will fail anyway in this case. Cc: stable@vger.kernel.org Reported-by: Benoît Sevens <bsevens@google.com> Fixes: 0bdd2ed4138e ("sched: run_posix_cpu_timers: Don't check ->exit_state, use lock_task_sighand()") Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-06-13io_uring/kbuf: don't truncate end buffer for multiple buffer peeksJens Axboe1-1/+4
If peeking a bunch of buffers, normally io_ring_buffers_peek() will truncate the end buffer. This isn't optimal as presumably more data will be arriving later, and hence it's better to stop with the last full buffer rather than truncate the end buffer. Cc: stable@vger.kernel.org Fixes: 35c8711c8fc4 ("io_uring/kbuf: add helpers for getting/peeking multiple buffers") Reported-by: Christian Mazakas <christian.mazakas@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-06-13Documentation: ublk: Separate UBLK_F_AUTO_BUF_REG fallback behavior sublistsBagas Sanjaya1-0/+2
Stephen Rothwell reports htmldocs warning on ublk docs: Documentation/block/ublk.rst:414: ERROR: Unexpected indentation. [docutils] Fix the warning by separating sublists of auto buffer registration fallback behavior from their appropriate parent list item. Fixes: ff20c516485e ("ublk: document auto buffer registration(UBLK_F_AUTO_BUF_REG)") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Closes: https://lore.kernel.org/linux-next/20250612132638.193de386@canb.auug.org.au/ Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Link: https://lore.kernel.org/r/20250613023857.15971-1-bagasdotme@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-06-13iommu/tegra: Fix incorrect size calculationJason Gunthorpe1-2/+2
This driver uses a mixture of ways to get the size of a PTE, tegra_smmu_set_pde() did it as sizeof(*pd) which became wrong when pd switched to a struct tegra_pd. Switch pd back to a u32* in tegra_smmu_set_pde() so the sizeof(*pd) returns 4. Fixes: 50568f87d1e2 ("iommu/terga: Do not use struct page as the handle for as->pd memory") Reported-by: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt> Closes: https://lore.kernel.org/all/62e7f7fe-6200-4e4f-ad42-d58ad272baa6@tecnico.ulisboa.pt/ Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Thierry Reding <treding@nvidia.com> Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> Tested-by: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt> Link: https://lore.kernel.org/r/0-v1-da7b8b3d57eb+ce-iommu_terga_sizeof_jgg@nvidia.com Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-06-13block: Fix bvec_set_folio() for very large foliosMatthew Wilcox (Oracle)1-2/+5
Similarly to 26064d3e2b4d ("block: fix adding folio to bio"), if we attempt to add a folio that is larger than 4GB, we'll silently truncate the offset and len. Widen the parameters to size_t, assert that the length is less than 4GB and set the first page that contains the interesting data rather than the first page of the folio. Fixes: 26db5ee15851 (block: add a bvec_set_folio helper) Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Link: https://lore.kernel.org/r/20250612144255.2850278-1-willy@infradead.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-06-13bio: Fix bio_first_folio() for SPARSEMEM without VMEMMAPMatthew Wilcox (Oracle)1-1/+1
It is possible for physically contiguous folios to have discontiguous struct pages if SPARSEMEM is enabled and SPARSEMEM_VMEMMAP is not. This is correctly handled by folio_page_idx(), so remove this open-coded implementation. Fixes: 640d1930bef4 (block: Add bio_for_each_folio_all()) Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Link: https://lore.kernel.org/r/20250612144126.2849931-1-willy@infradead.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-06-13spi: spi-pci1xxxx: Drop MSI-X usage as unsupported by DMA engineThangaraj Samynathan1-1/+1
Removes MSI-X from the interrupt request path, as the DMA engine used by the SPI controller does not support MSI-X interrupts. Signed-off-by: Thangaraj Samynathan <thangaraj.s@microchip.com> Link: https://patch.msgid.link/20250612023059.71726-1-thangaraj.s@microchip.com Signed-off-by: Mark Brown <broonie@kernel.org>
2025-06-12mm: add mmap_prepare() compatibility layer for nested file systemsLorenzo Stoakes5-3/+107
Nested file systems, that is those which invoke call_mmap() within their own f_op->mmap() handlers, may encounter underlying file systems which provide the f_op->mmap_prepare() hook introduced by commit c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file callback"). We have a chicken-and-egg scenario here - until all file systems are converted to using .mmap_prepare(), we cannot convert these nested handlers, as we can't call f_op->mmap from an .mmap_prepare() hook. So we have to do it the other way round - invoke the .mmap_prepare() hook from an .mmap() one. in order to do so, we need to convert VMA state into a struct vm_area_desc descriptor, invoking the underlying file system's f_op->mmap_prepare() callback passing a pointer to this, and then setting VMA state accordingly and safely. This patch achieves this via the compat_vma_mmap_prepare() function, which we invoke from call_mmap() if f_op->mmap_prepare() is specified in the passed in file pointer. We place the fundamental logic into mm/vma.h where VMA manipulation belongs. We also update the VMA userland tests to accommodate the changes. The compat_vma_mmap_prepare() function and its associated machinery is temporary, and will be removed once the conversion of file systems is complete. We carefully place this code so it can be used with CONFIG_MMU and also with cutting edge nommu silicon. [akpm@linux-foundation.org: export compat_vma_mmap_prepare tp fix build] [lorenzo.stoakes@oracle.com: remove unused declarations] Link: https://lkml.kernel.org/r/ac3ae324-4c65-432a-8c6d-2af988b18ac8@lucifer.local Link: https://lkml.kernel.org/r/20250609165749.344976-1-lorenzo.stoakes@oracle.com Fixes: c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file callback"). Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reported-by: Jann Horn <jannh@google.com> Closes: https://lore.kernel.org/linux-mm/CAG48ez04yOEVx1ekzOChARDDBZzAKwet8PEoPM4Ln3_rk91AzQ@mail.gmail.com/ Reviewed-by: Pedro Falcato <pfalcato@suse.de> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-06-12smb: improve directory cache reuse for readdir operationsBharath SM2-17/+19
Currently, cached directory contents were not reused across subsequent 'ls' operations because the cache validity check relied on comparing the ctx pointer, which changes with each readdir invocation. As a result, the cached dir entries was not marked as valid and the cache was not utilized for subsequent 'ls' operations. This change uses the file pointer, which remains consistent across all readdir calls for a given directory instance, to associate and validate the cache. As a result, cached directory contents can now be correctly reused, improving performance for repeated directory listings. Performance gains with local windows SMB server: Without the patch and default actimeo=1: 1000 directory enumeration operations on dir with 10k files took 135.0s With this patch and actimeo=0: 1000 directory enumeration operations on dir with 10k files took just 5.1s Signed-off-by: Bharath SM <bharathsm@microsoft.com> Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> Cc: stable@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com>
2025-06-12smb: client: fix perf regression with deferred closesPaulo Alcantara1-3/+6
Customer reported that one of their applications started failing to open files with STATUS_INSUFFICIENT_RESOURCES due to NetApp server hitting the maximum number of opens to same file that it would allow for a single client connection. It turned out the client was failing to reuse open handles with deferred closes because matching ->f_flags directly without masking off O_CREAT|O_EXCL|O_TRUNC bits first broke the comparision and then client ended up with thousands of deferred closes to same file. Those bits are already satisfied on the original open, so no need to check them against existing open handles. Reproducer: #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <fcntl.h> #include <pthread.h> #define NR_THREADS 4 #define NR_ITERATIONS 2500 #define TEST_FILE "/mnt/1/test/dir/foo" static char buf[64]; static void *worker(void *arg) { int i, j; int fd; for (i = 0; i < NR_ITERATIONS; i++) { fd = open(TEST_FILE, O_WRONLY|O_CREAT|O_APPEND, 0666); for (j = 0; j < 16; j++) write(fd, buf, sizeof(buf)); close(fd); } } int main(int argc, char *argv[]) { pthread_t t[NR_THREADS]; int fd; int i; fd = open(TEST_FILE, O_WRONLY|O_CREAT|O_TRUNC, 0666); close(fd); memset(buf, 'a', sizeof(buf)); for (i = 0; i < NR_THREADS; i++) pthread_create(&t[i], NULL, worker, NULL); for (i = 0; i < NR_THREADS; i++) pthread_join(t[i], NULL); return 0; } Before patch: $ mount.cifs //srv/share /mnt/1 -o ... $ mkdir -p /mnt/1/test/dir $ gcc repro.c && ./a.out ... number of opens: 1391 After patch: $ mount.cifs //srv/share /mnt/1 -o ... $ mkdir -p /mnt/1/test/dir $ gcc repro.c && ./a.out ... number of opens: 1 Cc: linux-cifs@vger.kernel.org Cc: David Howells <dhowells@redhat.com> Cc: Jay Shin <jaeshin@redhat.com> Cc: Pierguido Lambri <plambri@redhat.com> Fixes: b8ea3b1ff544 ("smb: enable reuse of deferred file handles for write operations") Acked-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-06-12drm/xe/lrc: Use a temporary buffer for WA BBLucas De Marchi1-4/+20
In case the BO is in iomem, we can't simply take the vaddr and write to it. Instead, prepare a separate buffer that is later copied into io memory. Right now it's just a few words that could be using xe_map_write32(), but the intention is to grow the WA BB for other uses. Fixes: 617d824c5323 ("drm/xe: Add WA BB to capture active context utilization") Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@igalia.com> Reviewed-by: Matthew Brost <matthew.brost@intel.com> Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com> Link: https://lore.kernel.org/r/20250604-wa-bb-fix-v1-1-0dfc5dafcef0@intel.com Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> (cherry picked from commit ef48715b2d3df17c060e23b9aa636af3d95652f8) Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
2025-06-12selftests: drv-net: rss_ctx: Add test for ntuple rules targeting default RSS contextGal Pressman1-1/+58
Add test_rss_default_context_rule() to verify that ntuple rules can correctly direct traffic to the default RSS context (context 0). The test creates two ntuple rules with explicit location priorities: - A high-priority rule (loc 0) directing specific port traffic to context 0. - A low-priority rule (loc 1) directing all other TCP traffic to context 1. This validates that: 1. Rules targeting the default context function properly. 2. Traffic steering works as expected when mixing default and additional RSS contexts. The test was written by AI, and reviewed by humans. Reviewed-by: Nimrod Oren <noren@nvidia.com> Signed-off-by: Gal Pressman <gal@nvidia.com> Link: https://patch.msgid.link/20250612071958.1696361-3-gal@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-12net: ethtool: Don't check if RSS context exists in case of context 0Gal Pressman1-1/+2
Context 0 (default context) always exists, there is no need to check whether it exists or not when adding a flow steering rule. The existing check fails when creating a flow steering rule for context 0 as it is not stored in the rss_ctx xarray. For example: $ ethtool --config-ntuple eth2 flow-type tcp4 dst-ip 194.237.147.23 dst-port 19983 context 0 loc 618 rmgr: Cannot insert RX class rule: Invalid argument Cannot insert classification rule An example usecase for this could be: - A high-priority rule (loc 0) directing specific port traffic to context 0. - A low-priority rule (loc 1) directing all other TCP traffic to context 1. This is a user-visible regression that was caught in our testing environment, it was not reported by a user yet. Fixes: de7f7582dff2 ("net: ethtool: prevent flow steering to RSS contexts which don't exist") Reviewed-by: Tariq Toukan <tariqt@nvidia.com> Reviewed-by: Nimrod Oren <noren@nvidia.com> Signed-off-by: Gal Pressman <gal@nvidia.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Edward Cree <ecree.xilinx@gmail.com> Link: https://patch.msgid.link/20250612071958.1696361-2-gal@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-12af_unix: Allow passing cred for embryo without SO_PASSCRED/SO_PASSPIDFD.Kuniyuki Iwashima1-1/+2
Before the cited commit, the kernel unconditionally embedded SCM credentials to skb for embryo sockets even when both the sender and listener disabled SO_PASSCRED and SO_PASSPIDFD. Now, the credentials are added to skb only when configured by the sender or the listener. However, as reported in the link below, it caused a regression for some programs that assume credentials are included in every skb, but sometimes not now. The only problematic scenario would be that a socket starts listening before setting the option. Then, there will be 2 types of non-small race window, where a client can send skb without credentials, which the peer receives as an "invalid" message (and aborts the connection it seems ?): Client Server ------ ------ s1.listen() <-- No SO_PASS{CRED,PIDFD} s2.connect() s2.send() <-- w/o cred s1.setsockopt(SO_PASS{CRED,PIDFD}) s2.send() <-- w/ cred or Client Server ------ ------ s1.listen() <-- No SO_PASS{CRED,PIDFD} s2.connect() s2.send() <-- w/o cred s3, _ = s1.accept() <-- Inherit cred options s2.send() <-- w/o cred but not set yet s3.setsockopt(SO_PASS{CRED,PIDFD}) s2.send() <-- w/ cred It's unfortunate that buggy programs depend on the behaviour, but let's restore the previous behaviour. Fixes: 3f84d577b79d ("af_unix: Inherit sk_flags at connect().") Reported-by: Jacek Łuczak <difrost.kernel@gmail.com> Closes: https://lore.kernel.org/all/68d38b0b-1666-4974-85d4-15575789c8d4@gmail.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Tested-by: Christian Heusel <christian@heusel.eu> Tested-by: André Almeida <andrealmeid@igalia.com> Tested-by: Jacek Łuczak <difrost.kernel@gmail.com> Link: https://patch.msgid.link/20250611202758.3075858-1-kuni1840@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-12ipv6: Move fib6_config_validate() to ip6_route_add().Kuniyuki Iwashima1-55/+55
syzkaller created an IPv6 route from a malformed packet, which has a prefix len > 128, triggering the splat below. [0] This is a similar issue fixed by commit 586ceac9acb7 ("ipv6: Restore fib6_config validation for SIOCADDRT."). The cited commit removed fib6_config validation from some callers of ip6_add_route(). Let's move the validation back to ip6_route_add() and ip6_route_multipath_add(). [0]: UBSAN: array-index-out-of-bounds in ./include/net/ipv6.h:616:34 index 20 is out of range for type '__u8 [16]' CPU: 1 UID: 0 PID: 7444 Comm: syz.0.708 Not tainted 6.16.0-rc1-syzkaller-g19272b37aa4f #0 PREEMPT Hardware name: riscv-virtio,qemu (DT) Call Trace: [<ffffffff80078a80>] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:132 [<ffffffff8000327a>] show_stack+0x30/0x3c arch/riscv/kernel/stacktrace.c:138 [<ffffffff80061012>] __dump_stack lib/dump_stack.c:94 [inline] [<ffffffff80061012>] dump_stack_lvl+0x12e/0x1a6 lib/dump_stack.c:120 [<ffffffff800610a6>] dump_stack+0x1c/0x24 lib/dump_stack.c:129 [<ffffffff8001c0ea>] ubsan_epilogue+0x14/0x46 lib/ubsan.c:233 [<ffffffff819ba290>] __ubsan_handle_out_of_bounds+0xf6/0xf8 lib/ubsan.c:455 [<ffffffff85b363a4>] ipv6_addr_prefix include/net/ipv6.h:616 [inline] [<ffffffff85b363a4>] ip6_route_info_create+0x8f8/0x96e net/ipv6/route.c:3793 [<ffffffff85b635da>] ip6_route_add+0x2a/0x1aa net/ipv6/route.c:3889 [<ffffffff85b02e08>] addrconf_prefix_route+0x2c4/0x4e8 net/ipv6/addrconf.c:2487 [<ffffffff85b23bb2>] addrconf_prefix_rcv+0x1720/0x1e62 net/ipv6/addrconf.c:2878 [<ffffffff85b92664>] ndisc_router_discovery+0x1a06/0x3504 net/ipv6/ndisc.c:1570 [<ffffffff85b99038>] ndisc_rcv+0x500/0x600 net/ipv6/ndisc.c:1874 [<ffffffff85bc2c18>] icmpv6_rcv+0x145e/0x1e0a net/ipv6/icmp.c:988 [<ffffffff85af6798>] ip6_protocol_deliver_rcu+0x18a/0x1976 net/ipv6/ip6_input.c:436 [<ffffffff85af8078>] ip6_input_finish+0xf4/0x174 net/ipv6/ip6_input.c:480 [<ffffffff85af8262>] NF_HOOK include/linux/netfilter.h:317 [inline] [<ffffffff85af8262>] NF_HOOK include/linux/netfilter.h:311 [inline] [<ffffffff85af8262>] ip6_input+0x16a/0x70c net/ipv6/ip6_input.c:491 [<ffffffff85af8dcc>] ip6_mc_input+0x5c8/0x1268 net/ipv6/ip6_input.c:588 [<ffffffff85af6112>] dst_input include/net/dst.h:469 [inline] [<ffffffff85af6112>] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline] [<ffffffff85af6112>] NF_HOOK include/linux/netfilter.h:317 [inline] [<ffffffff85af6112>] NF_HOOK include/linux/netfilter.h:311 [inline] [<ffffffff85af6112>] ipv6_rcv+0x5ae/0x6e0 net/ipv6/ip6_input.c:309 [<ffffffff85087e84>] __netif_receive_skb_one_core+0x106/0x16e net/core/dev.c:5977 [<ffffffff85088104>] __netif_receive_skb+0x2c/0x144 net/core/dev.c:6090 [<ffffffff850883c6>] netif_receive_skb_internal net/core/dev.c:6176 [inline] [<ffffffff850883c6>] netif_receive_skb+0x1aa/0xbf2 net/core/dev.c:6235 [<ffffffff8328656e>] tun_rx_batched.isra.0+0x430/0x686 drivers/net/tun.c:1485 [<ffffffff8329ed3a>] tun_get_user+0x2952/0x3d6c drivers/net/tun.c:1938 [<ffffffff832a21e0>] tun_chr_write_iter+0xc4/0x21c drivers/net/tun.c:1984 [<ffffffff80b9b9ae>] new_sync_write fs/read_write.c:593 [inline] [<ffffffff80b9b9ae>] vfs_write+0x56c/0xa9a fs/read_write.c:686 [<ffffffff80b9c2be>] ksys_write+0x126/0x228 fs/read_write.c:738 [<ffffffff80b9c42e>] __do_sys_write fs/read_write.c:749 [inline] [<ffffffff80b9c42e>] __se_sys_write fs/read_write.c:746 [inline] [<ffffffff80b9c42e>] __riscv_sys_write+0x6e/0x94 fs/read_write.c:746 [<ffffffff80076912>] syscall_handler+0x94/0x118 arch/riscv/include/asm/syscall.h:112 [<ffffffff8637e31e>] do_trap_ecall_u+0x396/0x530 arch/riscv/kernel/traps.c:341 [<ffffffff863a69e2>] handle_exception+0x146/0x152 arch/riscv/kernel/entry.S:197 Fixes: fa76c1674f2e ("ipv6: Move some validation from ip6_route_info_create() to rtm_to_fib6_config().") Reported-by: syzbot+4c2358694722d304c44e@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6849b8c3.a00a0220.1eb5f5.00f0.GAE@google.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250611193551.2999991-1-kuni1840@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-12net: drv: netdevsim: don't napi_complete() from netpollJakub Kicinski1-1/+2
netdevsim supports netpoll. Make sure we don't call napi_complete() from it, since it may not be scheduled. Breno reports hitting a warning in napi_complete_done(): WARNING: CPU: 14 PID: 104 at net/core/dev.c:6592 napi_complete_done+0x2cc/0x560 __napi_poll+0x2d8/0x3a0 handle_softirqs+0x1fe/0x710 This is presumably after netpoll stole the SCHED bit prematurely. Reported-by: Breno Leitao <leitao@debian.org> Fixes: 3762ec05a9fb ("netdevsim: add NAPI support") Tested-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20250611174643.2769263-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-12net/mlx5: HWS, Add error checking to hws_bwc_rule_complex_hash_node_get()Dan Carpenter1-2/+17
Check for if ida_alloc() or rhashtable_lookup_get_insert_fast() fails. Fixes: 17e0accac577 ("net/mlx5: HWS, support complex matchers") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Yevgeny Kliteynik <kliteyn@nvidia.com> Link: https://patch.msgid.link/aEmBONjyiF6z5yCV@stanley.mountain Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-12veth: prevent NULL pointer dereference in veth_xdp_rcvJesper Dangaard Brouer1-2/+2
The veth peer device is RCU protected, but when the peer device gets deleted (veth_dellink) then the pointer is assigned NULL (via RCU_INIT_POINTER). This patch adds a necessary NULL check in veth_xdp_rcv when accessing the veth peer net_device. This fixes a bug introduced in commit dc82a33297fc ("veth: apply qdisc backpressure on full ptr_ring to reduce TX drops"). The bug is a race and only triggers when having inflight packets on a veth that is being deleted. Reported-by: Ihor Solodrai <ihor.solodrai@linux.dev> Closes: https://lore.kernel.org/all/fecfcad0-7a16-42b8-bff2-66ee83a6e5c4@linux.dev/ Reported-by: syzbot+c4c7bf27f6b0c4bd97fe@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/683da55e.a00a0220.d8eae.0052.GAE@google.com/ Fixes: dc82a33297fc ("veth: apply qdisc backpressure on full ptr_ring to reduce TX drops") Signed-off-by: Jesper Dangaard Brouer <hawk@kernel.org> Acked-by: Ihor Solodrai <ihor.solodrai@linux.dev> Link: https://patch.msgid.link/174964557873.519608.10855046105237280978.stgit@firesoul Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-12net_sched: remove qdisc_tree_flush_backlog()Eric Dumazet1-8/+0
This function is no longer used after the four prior fixes. Given all prior uses were wrong, it seems better to remove it. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250611111515.1983366-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-12net_sched: ets: fix a race in ets_qdisc_change()Eric Dumazet1-1/+1
Gerrard Tai reported a race condition in ETS, whenever SFQ perturb timer fires at the wrong time. The race is as follows: CPU 0 CPU 1 [1]: lock root [2]: qdisc_tree_flush_backlog() [3]: unlock root | | [5]: lock root | [6]: rehash | [7]: qdisc_tree_reduce_backlog() | [4]: qdisc_put() This can be abused to underflow a parent's qlen. Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog() should fix the race, because all packets will be purged from the qdisc before releasing the lock. Fixes: b05972f01e7d ("net: sched: tbf: don't call qdisc_put() while holding tree lock") Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg> Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250611111515.1983366-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>