These functions can be executed on the int3 stack, so kprobes are
dangerous. Tracing is probably a bad idea, too.
Fixes: b645af2d5905c4e32399005b867987919cbfc3ae
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
---
This is only lightly tested, but it seems like a good idea. Sorry I
missed this over the weekend.
I don't think there's any rush on this, but I'll discourage the -stable
people from applying the bad_iret fix until this is in.
Actually, it's probably best for the -stable kernels to hold off on both
b645af2d5905 x86_64, traps: Rework bad_iret
and
af726f21ed8a x86_64, traps: Fix the espfix64 #DF fixup and rewrite it in C
for a couple weeks so that they can accumulate some more testing. They're
security fixes, but the impact is probably so low that there's no rush.
arch/x86/kernel/traps.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index de801f22128a..07ab8e9733c5 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -387,7 +387,7 @@ NOKPROBE_SYMBOL(do_int3);
* for scheduling or signal handling. The actual stack switch is done in
* entry.S
*/
-asmlinkage __visible struct pt_regs *sync_regs(struct pt_regs *eregs)
+asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs)
{
struct pt_regs *regs = eregs;
/* Did already sync */
@@ -413,7 +413,7 @@ struct bad_iret_stack {
struct pt_regs regs;
};
-asmlinkage __visible
+asmlinkage __visible notrace
struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s)
{
/*
@@ -436,6 +436,7 @@ struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s)
BUG_ON(!user_mode_vm(&new_stack->regs));
return new_stack;
}
+NOKPROBE_SYMBOL(fixup_bad_iret);
#endif
/*
--
1.9.3
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html