From: Eric W. Biederman Date: Thu, 4 Jan 2018 01:04:34 +0000 (-0600) Subject: x86/mm/pkeys: Fix fill_sig_info_pkey X-Git-Tag: v5.15~9558^2~32 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=90bc9fb15942ad08b46cd003d8d1b51f3d43e322;p=mirror_ubuntu-kernels.git 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. I found this error by inspection, and BUS_MCEERR_AR appears to be a real candidate for confusion. So pass in si_signo and fix it. Cc: Dave Hansen Cc: Thomas Gleixner Cc: Ingo Molnar Fixes: 019132ff3daf ("x86/mm/pkeys: Fill in pkey field in siginfo") Signed-off-by: "Eric W. Biederman" --- diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 06fe3d51d385..b3e40773dce0 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); }