android/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

x86/kprobes: Update kcb status flag after singlestepping

Browse Source 
[ 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@posteo.net>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Daniel Müller <deso@posteo.net>
Cc: stable@vger.kernel.org
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@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Masami Hiramatsu (Google) 2023-07-05 14:46:52 +08:00 committed by Greg Kroah-Hartman
parent f07f3938c8
commit edc2ac7c72
1 changed files with 11 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
arch/x86/kernel/kprobes/core.c
View File

@ -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);