Messages in this thread Patch in this message | | | Date | Wed, 16 Jul 2014 12:23:49 -0700 | From | tip-bot for Andy Lutomirski <> | Subject | [tip:perf/urgent] kprobes/x86: Don' t try to resolve kprobe faults from userspace |
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Commit-ID: 0cdd192cf40fb6dbf03ec3af1c670068de3fd26c Gitweb: http://git.kernel.org/tip/0cdd192cf40fb6dbf03ec3af1c670068de3fd26c Author: Andy Lutomirski <luto@amacapital.net> AuthorDate: Fri, 11 Jul 2014 10:27:01 -0700 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Wed, 16 Jul 2014 14:16:32 +0200
kprobes/x86: Don't try to resolve kprobe faults from userspace
This commit:
commit 6f6343f53d133bae516caf3d254bce37d8774625 Author: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Date: Thu Apr 17 17:17:33 2014 +0900
kprobes/x86: Call exception handlers directly from do_int3/do_debug
appears to have inadvertently dropped a check that the int3 came from kernel mode. Trying to dereference addr when addr is user-controlled is completely bogus.
Signed-off-by: Andy Lutomirski <luto@amacapital.net> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Link: http://lkml.kernel.org/r/c4e339882c121aa76254f2adde3fcbdf502faec2.1405099506.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/kernel/kprobes/core.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 7596df6..67e6d19 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -574,6 +574,9 @@ int kprobe_int3_handler(struct pt_regs *regs) struct kprobe *p; struct kprobe_ctlblk *kcb; + if (user_mode_vm(regs)) + return 0; + addr = (kprobe_opcode_t *)(regs->ip - sizeof(kprobe_opcode_t)); /* * We don't want to be preempted for the entire
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