laptop-kernel/fs/f2fs, branch master

f2fs: fix use-after-free of sbi in f2fs_compress_write_end_io()

2026-04-27T13:30:18Z

commit 39d4ee19c1e7d753dd655aebee632271b171f43a upstream. In f2fs_compress_write_end_io(), dec_page_count(sbi, type) can bring the F2FS_WB_CP_DATA counter to zero, unblocking f2fs_wait_on_all_pages() in f2fs_put_super() on a concurrent unmount CPU. The unmount path then proceeds to call f2fs_destroy_page_array_cache(sbi), which destroys sbi->page_array_slab via kmem_cache_destroy(), and eventually kfree(sbi). Meanwhile, the bio completion callback is still executing: when it reaches page_array_free(sbi, ...), it dereferences sbi->page_array_slab — a destroyed slab cache — to call kmem_cache_free(), causing a use-after-free. This is the same class of bug as CVE-2026-23234 (which fixed the equivalent race in f2fs_write_end_io() in data.c), but in the compressed writeback completion path that was not covered by that fix. Fix this by moving dec_page_count() to after page_array_free(), so that all sbi accesses complete before the counter decrement that can unblock unmount. For non-last folios (where atomic_dec_return on cic->pending_pages is nonzero), dec_page_count is called immediately before returning — page_array_free is not reached on this path, so there is no post-decrement sbi access. For the last folio, page_array_free runs while the F2FS_WB_CP_DATA counter is still nonzero (this folio has not yet decremented it), keeping sbi alive, and dec_page_count runs as the final operation. Fixes: 4c8ff7095bef ("f2fs: support data compression") Cc: stable@vger.kernel.org Signed-off-by: George Saad Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman

f2fs: fix to avoid uninit-value access in f2fs_sanity_check_node_footer

2026-04-27T13:30:17Z

commit 7b9161a605e91d0987e2596a245dc1f21621b23f upstream. syzbot reported a f2fs bug as below: BUG: KMSAN: uninit-value in f2fs_sanity_check_node_footer+0x374/0xa20 fs/f2fs/node.c:1520 f2fs_sanity_check_node_footer+0x374/0xa20 fs/f2fs/node.c:1520 f2fs_finish_read_bio+0xe1e/0x1d60 fs/f2fs/data.c:177 f2fs_read_end_io+0x6ab/0x2220 fs/f2fs/data.c:-1 bio_endio+0x1006/0x1160 block/bio.c:1792 submit_bio_noacct+0x533/0x2960 block/blk-core.c:891 submit_bio+0x57a/0x620 block/blk-core.c:926 blk_crypto_submit_bio include/linux/blk-crypto.h:203 [inline] f2fs_submit_read_bio+0x12c/0x360 fs/f2fs/data.c:557 f2fs_submit_page_bio+0xee2/0x1450 fs/f2fs/data.c:775 read_node_folio+0x384/0x4b0 fs/f2fs/node.c:1481 __get_node_folio+0x5db/0x15d0 fs/f2fs/node.c:1576 f2fs_get_inode_folio+0x40/0x50 fs/f2fs/node.c:1623 do_read_inode fs/f2fs/inode.c:425 [inline] f2fs_iget+0x1209/0x9380 fs/f2fs/inode.c:596 f2fs_fill_super+0x8f5a/0xb2e0 fs/f2fs/super.c:5184 get_tree_bdev_flags+0x6e6/0x920 fs/super.c:1694 get_tree_bdev+0x38/0x50 fs/super.c:1717 f2fs_get_tree+0x35/0x40 fs/f2fs/super.c:5436 vfs_get_tree+0xb3/0x5d0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3763 [inline] do_new_mount+0x885/0x1dd0 fs/namespace.c:3839 path_mount+0x7a2/0x20b0 fs/namespace.c:4159 do_mount fs/namespace.c:4172 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount+0x704/0x7f0 fs/namespace.c:4338 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4338 x64_sys_call+0x39f0/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x134/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The root cause is: in f2fs_finish_read_bio(), we may access uninit data in folio if we failed to read the data from device into folio, let's add a check condition to avoid such issue. Cc: stable@kernel.org Fixes: 50ac3ecd8e05 ("f2fs: fix to do sanity check on node footer in {read,write}_end_io") Reported-by: syzbot+9aac813cdc456cdd49f8@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-f2fs-devel/69a9ca26.a70a0220.305d9a.0000.GAE@google.com Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman

f2fs: fix to avoid memory leak in f2fs_rename()

2026-04-27T13:30:17Z

commit 3cf11e6f36c170050c12171dd6fd3142711478fc upstream. syzbot reported a f2fs bug as below: BUG: memory leak unreferenced object 0xffff888127f70830 (size 16): comm "syz.0.23", pid 6144, jiffies 4294943712 hex dump (first 16 bytes): 3c af 57 72 5b e6 8f ad 6e 8e fd 33 42 39 03 ff <.Wr[...n..3B9.. backtrace (crc 925f8a80): kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline] slab_post_alloc_hook mm/slub.c:4520 [inline] slab_alloc_node mm/slub.c:4844 [inline] __do_kmalloc_node mm/slub.c:5237 [inline] __kmalloc_noprof+0x3bd/0x560 mm/slub.c:5250 kmalloc_noprof include/linux/slab.h:954 [inline] fscrypt_setup_filename+0x15e/0x3b0 fs/crypto/fname.c:364 f2fs_setup_filename+0x52/0xb0 fs/f2fs/dir.c:143 f2fs_rename+0x159/0xca0 fs/f2fs/namei.c:961 f2fs_rename2+0xd5/0xf20 fs/f2fs/namei.c:1308 vfs_rename+0x7ff/0x1250 fs/namei.c:6026 filename_renameat2+0x4f4/0x660 fs/namei.c:6144 __do_sys_renameat2 fs/namei.c:6173 [inline] __se_sys_renameat2 fs/namei.c:6168 [inline] __x64_sys_renameat2+0x59/0x80 fs/namei.c:6168 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The root cause is in commit 40b2d55e0452 ("f2fs: fix to create selinux label during whiteout initialization"), we added a call to f2fs_setup_filename() without a matching call to f2fs_free_filename(), fix it. Fixes: 40b2d55e0452 ("f2fs: fix to create selinux label during whiteout initialization") Cc: stable@kernel.org Reported-by: syzbot+cf7946ab25b21abc4b66@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-f2fs-devel/69a75fe1.a70a0220.b118c.0014.GAE@google.com Suggested-by: Eric Biggers Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman

f2fs: fix UAF caused by decrementing sbi->nr_pages[] in f2fs_write_end_io()

2026-04-27T13:30:17Z

commit 2d9c4a4ed4eef1f82c5b16b037aee8bad819fd53 upstream. The xfstests case "generic/107" and syzbot have both reported a NULL pointer dereference. The concurrent scenario that triggers the panic is as follows: F2FS_WB_CP_DATA write callback umount - f2fs_write_checkpoint - f2fs_wait_on_all_pages(sbi, F2FS_WB_CP_DATA) - blk_mq_end_request - bio_endio - f2fs_write_end_io : dec_page_count(sbi, F2FS_WB_CP_DATA) : wake_up(&sbi->cp_wait) - kill_f2fs_super - kill_block_super - f2fs_put_super : iput(sbi->node_inode) : sbi->node_inode = NULL : f2fs_in_warm_node_list - is_node_folio // sbi->node_inode is NULL and panic The root cause is that f2fs_put_super() calls iput(sbi->node_inode) and sets sbi->node_inode to NULL after sbi->nr_pages[F2FS_WB_CP_DATA] is decremented to zero. As a result, f2fs_in_warm_node_list() may dereference a NULL node_inode when checking whether a folio belongs to the node inode, leading to a panic. This patch fixes the issue by calling f2fs_in_warm_node_list() before decrementing sbi->nr_pages[F2FS_WB_CP_DATA], thus preventing the use-after-free condition. Cc: stable@kernel.org Fixes: 50fa53eccf9f ("f2fs: fix to avoid broken of dnode block list") Reported-by: syzbot+6e4cb1cac5efc96ea0ca@syzkaller.appspotmail.com Signed-off-by: Yongpeng Yang Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman

f2fs: fix to do sanity check on dcc->discard_cmd_cnt conditionally

2026-04-27T13:30:17Z

commit 6af249c996f7d73a3435f9e577956fa259347d18 upstream. Syzbot reported a f2fs bug as below: ------------[ cut here ]------------ kernel BUG at fs/f2fs/segment.c:1900! Oops: invalid opcode: 0000 [#1] SMP KASAN PTI CPU: 1 UID: 0 PID: 6527 Comm: syz.5.110 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:f2fs_issue_discard_timeout+0x59b/0x5a0 fs/f2fs/segment.c:1900 Code: d9 80 e1 07 80 c1 03 38 c1 0f 8c d6 fe ff ff 48 89 df e8 a8 5e fa fd e9 c9 fe ff ff e8 4e 46 94 fd 90 0f 0b e8 46 46 94 fd 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 RSP: 0018:ffffc9000494f940 EFLAGS: 00010283 RAX: ffffffff843009ca RBX: 0000000000000001 RCX: 0000000000080000 RDX: ffffc9001ca78000 RSI: 00000000000029f3 RDI: 00000000000029f4 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed100893a431 R12: 1ffff1100893a430 R13: 1ffff1100c2b702c R14: dffffc0000000000 R15: ffff8880449d2160 FS: 00007ffa35fed6c0(0000) GS:ffff88812643d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2b68634000 CR3: 0000000039f62000 CR4: 00000000003526f0 Call Trace: __f2fs_remount fs/f2fs/super.c:2960 [inline] f2fs_reconfigure+0x108a/0x1710 fs/f2fs/super.c:5443 reconfigure_super+0x227/0x8a0 fs/super.c:1080 do_remount fs/namespace.c:3391 [inline] path_mount+0xdc5/0x10e0 fs/namespace.c:4151 do_mount fs/namespace.c:4172 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4338 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffa37dbda0a The root cause is there will be race condition in between f2fs_ioc_fitrim() and f2fs_remount(): - f2fs_remount - f2fs_ioc_fitrim - f2fs_issue_discard_timeout - __issue_discard_cmd - __drop_discard_cmd - __wait_all_discard_cmd - f2fs_trim_fs - f2fs_write_checkpoint - f2fs_clear_prefree_segments - f2fs_issue_discard - __issue_discard_async - __queue_discard_cmd - __update_discard_tree_range - __insert_discard_cmd - __create_discard_cmd : atomic_inc(&dcc->discard_cmd_cnt); - sanity check on dcc->discard_cmd_cnt (expect discard_cmd_cnt to be zero) This will only happen when fitrim races w/ remount rw, if we remount to readonly filesystem, remount will wait until mnt_pcp.mnt_writers to zero, that means fitrim is not in process at that time. Cc: stable@kernel.org Fixes: 2482c4325dfe ("f2fs: detect bug_on in f2fs_wait_discard_bios") Reported-by: syzbot+62538b67389ee582837a@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-f2fs-devel/69b07d7c.050a0220.8df7.09a1.GAE@google.com Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman

Merge tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fsverity/linux

2026-02-22T21:12:04Z

Pull fsverity fixes from Eric Biggers: - Fix a build error on parisc - Remove the non-large-folio-aware function fsverity_verify_page() * tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fsverity/linux: fsverity: fix build error by adding fsverity_readahead() stub fsverity: remove fsverity_verify_page() f2fs: make f2fs_verify_cluster() partially large-folio-aware f2fs: remove unnecessary ClearPageUptodate in f2fs_verify_cluster()

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51Z

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28Z

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

f2fs: make f2fs_verify_cluster() partially large-folio-aware

2026-02-18T07:11:36Z

f2fs_verify_cluster() is the only remaining caller of the non-large-folio-aware function fsverity_verify_page(). To unblock the removal of that function, change f2fs_verify_cluster() to verify the entire folio of each page and mark it up-to-date. Note that this doesn't actually make f2fs_verify_cluster() large-folio-aware, as it is still passed an array of pages. Currently, it's never called with large folios. Suggested-by: Matthew Wilcox Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20260218010630.7407-3-ebiggers@kernel.org Signed-off-by: Eric Biggers

f2fs: remove unnecessary ClearPageUptodate in f2fs_verify_cluster()

2026-02-18T07:11:36Z

Remove the unnecessary clearing of PG_uptodate. It's guaranteed to already be clear. Suggested-by: Matthew Wilcox Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20260218010630.7407-2-ebiggers@kernel.org Signed-off-by: Eric Biggers