diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2018-01-12 14:31:35 -0600 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-01-14 12:14:51 +0100 |
| commit | beacd6f7ed5e2915959442245b3b2480c2e37490 (patch) | |
| tree | 1338577480a05b6866172a22964631095614d756 | |
| parent | 4b5b2127238e689ee18aa6752959751dd61c4c73 (diff) | |
| download | linux-4.1-beacd6f7ed5e2915959442245b3b2480c2e37490.tar.gz | |
x86/mm/pkeys: Fix fill_sig_info_pkey
SEGV_PKUERR is a signal specific si_code which happens to have the same
numeric value as several others: BUS_MCEERR_AR, ILL_ILLTRP, FPE_FLTOVF,
TRAP_HWBKPT, CLD_TRAPPED, POLL_ERR, SEGV_THREAD_ID, as such it is not safe
to just test the si_code the signal number must also be tested to prevent a
false positive in fill_sig_info_pkey.
This error was by inspection, and BUS_MCEERR_AR appears to be a real
candidate for confusion. So pass in si_signo and check for SIG_SEGV to
verify that it is actually a SEGV_PKUERR
Fixes: 019132ff3daf ("x86/mm/pkeys: Fill in pkey field in siginfo")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180112203135.4669-2-ebiederm@xmission.com
| -rw-r--r-- | arch/x86/mm/fault.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 06fe3d51d385b8..b3e40773dce096 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -172,14 +172,15 @@ is_prefetch(struct pt_regs *regs, unsigned long error_code, unsigned long addr) * 6. T1 : reaches here, sees vma_pkey(vma)=5, when we really * faulted on a pte with its pkey=4. */ -static void fill_sig_info_pkey(int si_code, siginfo_t *info, u32 *pkey) +static void fill_sig_info_pkey(int si_signo, int si_code, siginfo_t *info, + u32 *pkey) { /* This is effectively an #ifdef */ if (!boot_cpu_has(X86_FEATURE_OSPKE)) return; /* Fault not from Protection Keys: nothing to do */ - if (si_code != SEGV_PKUERR) + if ((si_code != SEGV_PKUERR) || (si_signo != SIGSEGV)) return; /* * force_sig_info_fault() is called from a number of @@ -218,7 +219,7 @@ force_sig_info_fault(int si_signo, int si_code, unsigned long address, lsb = PAGE_SHIFT; info.si_addr_lsb = lsb; - fill_sig_info_pkey(si_code, &info, pkey); + fill_sig_info_pkey(si_signo, si_code, &info, pkey); force_sig_info(si_signo, &info, tsk); } |