From: Eric W. Biederman Date: Fri, 20 Jul 2018 01:48:30 +0000 (-0500) Subject: signal: Properly deliver SIGSEGV from x86 uprobes X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b7da2be19178ba02912b1a3c7e46b6ab4f050f92;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git signal: Properly deliver SIGSEGV from x86 uprobes [ Upstream commit 4a63c1ffd384ebdce40aac9c997dab68379137be ] For userspace to tell the difference between an random signal and an exception, the exception must include siginfo information. Using SEND_SIG_FORCED for SIGSEGV is thus wrong, and it will result in userspace seeing si_code == SI_USER (like a random signal) instead of si_code == SI_KERNEL or a more specific si_code as all exceptions deliver. Therefore replace force_sig_info(SIGSEGV, SEND_SIG_FORCE, current) with force_sig(SIG_SEGV, current) which gets this right and is shorter and easier to type. Fixes: 791eca10107f ("uretprobes/x86: Hijack return address") Reviewed-by: Thomas Gleixner Signed-off-by: "Eric W. Biederman" Signed-off-by: Sasha Levin --- diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 7a87ef1f5b5e..73391c1bd2a9 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -987,7 +987,7 @@ arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs pr_err("uprobe: return address clobbered: pid=%d, %%sp=%#lx, " "%%ip=%#lx\n", current->pid, regs->sp, regs->ip); - force_sig_info(SIGSEGV, SEND_SIG_FORCED, current); + force_sig(SIGSEGV, current); } return -1;