diff options
| author | Masami Hiramatsu <mhiramat@kernel.org> | 2019-09-03 20:08:21 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-05 12:30:26 +0200 |
| commit | d641e70f40f70e676093ecd8687c53393c463d97 (patch) | |
| tree | d90bf01db9171c42870f624b0d803307e5432842 | |
| parent | 1d2a860e355307bf4d555df8e2306faa1fdbcb72 (diff) | |
kprobes: Prohibit probing on BUG() and WARN() address
[ Upstream commit e336b4027775cb458dc713745e526fa1a1996b2a ]
Since BUG() and WARN() may use a trap (e.g. UD2 on x86) to
get the address where the BUG() has occurred, kprobes can not
do single-step out-of-line that instruction. So prohibit
probing on such address.
Without this fix, if someone put a kprobe on WARN(), the
kernel will crash with invalid opcode error instead of
outputing warning message, because kernel can not find
correct bug address.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S . Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naveen N . Rao <naveen.n.rao@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/156750890133.19112.3393666300746167111.stgit@devnote2
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | include/linux/bug.h | 5 | ||||
| -rw-r--r-- | kernel/kprobes.c | 3 |
2 files changed, 7 insertions, 1 deletions
diff --git a/include/linux/bug.h b/include/linux/bug.h index 292d6a10b0c2..0faae96302bd 100644 --- a/include/linux/bug.h +++ b/include/linux/bug.h @@ -114,6 +114,11 @@ int is_valid_bugaddr(unsigned long addr); #else /* !CONFIG_GENERIC_BUG */ +static inline void *find_bug(unsigned long bugaddr) +{ + return NULL; +} + static inline enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs) { diff --git a/kernel/kprobes.c b/kernel/kprobes.c index e2845dd53b30..11863e2b01c2 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1454,7 +1454,8 @@ static int check_kprobe_address_safe(struct kprobe *p, /* Ensure it is not in reserved area nor out of text */ if (!kernel_text_address((unsigned long) p->addr) || within_kprobe_blacklist((unsigned long) p->addr) || - jump_label_text_reserved(p->addr, p->addr)) { + jump_label_text_reserved(p->addr, p->addr) || + find_bug((unsigned long)p->addr)) { ret = -EINVAL; goto out; } |