From: Eric W. Biederman ebiederm@xmission.com
[ 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 tglx@linutronix.de Signed-off-by: "Eric W. Biederman" ebiederm@xmission.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kernel/uprobes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 7a87ef1f5b5e6..73391c1bd2a9a 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;