This is a note to let you know that I've just added the patch titled
x86/kprobes: Update kcb status flag after singlestepping
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-kprobes-update-kcb-status-flag-after-singlestepping.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From stable-owner@xxxxxxxxxxxxxxx Wed Jul 5 08:48:04 2023
From: Li Huafei <lihuafei1@xxxxxxxxxx>
Date: Wed, 5 Jul 2023 14:46:52 +0800
Subject: x86/kprobes: Update kcb status flag after singlestepping
To: <stable@xxxxxxxxxxxxxxx>
Cc: <gregkh@xxxxxxxxxxxxxxxxxxx>, <mhiramat@xxxxxxxxxx>, <tglx@xxxxxxxxxxxxx>, <mingo@xxxxxxxxxx>, <bp@xxxxxxxxx>, <x86@xxxxxxxxxx>, <hpa@xxxxxxxxx>, <sashal@xxxxxxxxxx>, <peterz@xxxxxxxxxxxxx>, <linux-kernel@xxxxxxxxxxxxxxx>, <xukuohai@xxxxxxxxxx>, <natechancellor@xxxxxxxxx>, <ndesaulniers@xxxxxxxxxx>, <rostedt@xxxxxxxxxxx>, <weiyongjun1@xxxxxxxxxx>, <gustavoars@xxxxxxxxxx>, <namit@xxxxxxxxxx>, <laijs@xxxxxxxxxxxxxxxxx>, <clang-built-linux@xxxxxxxxxxxxxxxx>, <lihuafei1@xxxxxxxxxx>
Message-ID: <20230705064653.226811-9-lihuafei1@xxxxxxxxxx>
From: "Masami Hiramatsu (Google)" <mhiramat@xxxxxxxxxx>
[ Upstream commit dec8784c9088b131a1523f582c2194cfc8107dc0 ]
Fix kprobes to update kcb (kprobes control block) status flag to
KPROBE_HIT_SSDONE even if the kp->post_handler is not set.
This bug may cause a kernel panic if another INT3 user runs right
after kprobes because kprobe_int3_handler() misunderstands the
INT3 is kprobe's single stepping INT3.
Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Reported-by: Daniel Müller <deso@xxxxxxxxxx>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Tested-by: Daniel Müller <deso@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/all/20220727210136.jjgc3lpqeq42yr3m@muellerd-fedora-PC2BDTX9
Link: https://lore.kernel.org/r/165942025658.342061.12452378391879093249.stgit@devnote2
Signed-off-by: Li Huafei <lihuafei1@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/kprobes/core.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -826,16 +826,20 @@ NOKPROBE_SYMBOL(arch_prepare_kretprobe);
static void kprobe_post_process(struct kprobe *cur, struct pt_regs *regs,
struct kprobe_ctlblk *kcb)
{
- if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
- kcb->kprobe_status = KPROBE_HIT_SSDONE;
- cur->post_handler(cur, regs, 0);
- }
-
/* Restore back the original saved kprobes variables and continue. */
- if (kcb->kprobe_status == KPROBE_REENTER)
+ if (kcb->kprobe_status == KPROBE_REENTER) {
+ /* This will restore both kcb and current_kprobe */
restore_previous_kprobe(kcb);
- else
+ } else {
+ /*
+ * Always update the kcb status because
+ * reset_curent_kprobe() doesn't update kcb.
+ */
+ kcb->kprobe_status = KPROBE_HIT_SSDONE;
+ if (cur->post_handler)
+ cur->post_handler(cur, regs, 0);
reset_current_kprobe();
+ }
}
NOKPROBE_SYMBOL(kprobe_post_process);
Patches currently in stable-queue which might be from stable-owner@xxxxxxxxxxxxxxx are
queue-5.10/x86-kprobes-update-kcb-status-flag-after-singlestepping.patch
queue-5.10/x86-kprobes-fix-to-identify-indirect-jmp-and-others-using-range-case.patch
queue-5.10/x86-kprobes-fix-jng-jnle-emulation.patch
queue-5.10/x86-kprobes-retrieve-correct-opcode-for-group-instruction.patch
queue-5.10/x86-kprobes-use-int3-instead-of-debug-trap-for-single-step.patch
queue-5.10/x86-kprobes-do-not-decode-opcode-in-resume_execution.patch
queue-5.10/x86-kprobes-identify-far-indirect-jmp-correctly.patch
queue-5.10/kprobes-x86-fix-fall-through-warnings-for-clang.patch
queue-5.10/x86-kprobes-move-inline-to-the-beginning-of-the-kprobe_is_ss-declaration.patch
