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| author |   Arnd Bergmann <arnd@arndb.de> | 2019-10-01 16:23:34 +0200 |
|---|---|---|
| committer |   Borislav Petkov <bp@suse.de> | 2019-10-03 10:51:08 +0200 |
| commit | e6b44ce1925a8329a937c57f0d60ba0d9bb5d226 (patch) | |
| tree | 9dd930fc72072d23f265fb8c869dffb2a9116499 /arch/x86/math-emu | |
| parent | x86/rdrand: Sanity-check RDRAND output (diff) | |
| download | linux-dev-e6b44ce1925a8329a937c57f0d60ba0d9bb5d226.tar.xz linux-dev-e6b44ce1925a8329a937c57f0d60ba0d9bb5d226.zip | |
x86/math-emu: Check __copy_from_user() result
The new __must_check annotation on __copy_from_user() successfully
identified some code that has lacked the check since at least
linux-2.1.73:
arch/x86/math-emu/reg_ld_str.c:88:2: error: ignoring return value of \
function declared with 'warn_unused_result' attribute [-Werror,-Wunused-result]
__copy_from_user(sti_ptr, s, 10);
^~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~
arch/x86/math-emu/reg_ld_str.c:1129:2: error: ignoring return value of \
function declared with 'warn_unused_result' attribute [-Werror,-Wunused-result]
__copy_from_user(register_base + offset, s, other);
^~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/math-emu/reg_ld_str.c:1131:3: error: ignoring return value of \
function declared with 'warn_unused_result' attribute [-Werror,-Wunused-result]
__copy_from_user(register_base, s + other, offset);
^~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In addition, the get_user()/put_user() helpers do not enforce a return
value check, but actually still require one. These have been missing for
even longer.
Change the internal wrappers around get_user()/put_user() to force
a signal and add a corresponding wrapper around __copy_from_user()
to check all such cases.
[ bp: Break long lines. ]
Fixes: 257e458057e5 ("Import 2.1.73")
Fixes: 9dd819a15162 ("uaccess: add missing __must_check attributes")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Bill Metzenthen <billm@melbpc.org.au>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191001142344.1274185-1-arnd@arndb.de
Diffstat (limited to 'arch/x86/math-emu')
| -rw-r--r-- | arch/x86/math-emu/fpu_system.h | 6 | ||||
| -rw-r--r-- | arch/x86/math-emu/reg_ld_str.c | 6 |
2 files changed, 7 insertions, 5 deletions
diff --git a/arch/x86/math-emu/fpu_system.h b/arch/x86/math-emu/fpu_system.h index f98a0c956764..9b41391867dc 100644 --- a/arch/x86/math-emu/fpu_system.h +++ b/arch/x86/math-emu/fpu_system.h @@ -107,6 +107,8 @@ static inline bool seg_writable(struct desc_struct *d) #define FPU_access_ok(y,z) if ( !access_ok(y,z) ) \ math_abort(FPU_info,SIGSEGV) #define FPU_abort math_abort(FPU_info, SIGSEGV) +#define FPU_copy_from_user(to, from, n) \ + do { if (copy_from_user(to, from, n)) FPU_abort; } while (0) #undef FPU_IGNORE_CODE_SEGV #ifdef FPU_IGNORE_CODE_SEGV @@ -122,7 +124,7 @@ static inline bool seg_writable(struct desc_struct *d) #define FPU_code_access_ok(z) FPU_access_ok((void __user *)FPU_EIP,z) #endif -#define FPU_get_user(x,y) get_user((x),(y)) -#define FPU_put_user(x,y) put_user((x),(y)) +#define FPU_get_user(x,y) do { if (get_user((x),(y))) FPU_abort; } while (0) +#define FPU_put_user(x,y) do { if (put_user((x),(y))) FPU_abort; } while (0) #endif diff --git a/arch/x86/math-emu/reg_ld_str.c b/arch/x86/math-emu/reg_ld_str.c index f3779743d15e..fe6246ff9887 100644 --- a/arch/x86/math-emu/reg_ld_str.c +++ b/arch/x86/math-emu/reg_ld_str.c @@ -85,7 +85,7 @@ int FPU_load_extended(long double __user *s, int stnr) RE_ENTRANT_CHECK_OFF; FPU_access_ok(s, 10); - __copy_from_user(sti_ptr, s, 10); + FPU_copy_from_user(sti_ptr, s, 10); RE_ENTRANT_CHECK_ON; return FPU_tagof(sti_ptr); @@ -1126,9 +1126,9 @@ void frstor(fpu_addr_modes addr_modes, u_char __user *data_address) /* Copy all registers in stack order. */ RE_ENTRANT_CHECK_OFF; FPU_access_ok(s, 80); - __copy_from_user(register_base + offset, s, other); + FPU_copy_from_user(register_base + offset, s, other); if (offset) - __copy_from_user(register_base, s + other, offset); + FPU_copy_from_user(register_base, s + other, offset); RE_ENTRANT_CHECK_ON; for (i = 0; i < 8; i++) { |