diff options
| author | Adam Zabrocki <[email protected]> | 2022-04-22 18:40:27 +0200 |
|---|---|---|
| committer | Daniel Borkmann <[email protected]> | 2022-04-26 16:09:36 +0200 |
| commit | 1d661ed54d8613c97bcff2c7d6181c61e482a1da (patch) | |
| tree | f126c3bcc98255dfed064c1ac7a95fc58e771613 | |
| parent | b02d196c44ead1a5949729be9ff08fe781c3e48a (diff) | |
kprobes: Fix KRETPROBES when CONFIG_KRETPROBE_ON_RETHOOK is set
The recent kernel change in 73f9b911faa7 ("kprobes: Use rethook for kretprobe
if possible"), introduced a potential NULL pointer dereference bug in the
KRETPROBE mechanism. The official Kprobes documentation defines that "Any or
all handlers can be NULL". Unfortunately, there is a missing return handler
verification to fulfill these requirements and can result in a NULL pointer
dereference bug.
This patch adds such verification in kretprobe_rethook_handler() function.
Fixes: 73f9b911faa7 ("kprobes: Use rethook for kretprobe if possible")
Signed-off-by: Adam Zabrocki <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Masami Hiramatsu <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Naveen N. Rao <[email protected]>
Cc: Anil S. Keshavamurthy <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
| -rw-r--r-- | kernel/kprobes.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index dbe57df2e199..dd58c0be9ce2 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2126,7 +2126,7 @@ static void kretprobe_rethook_handler(struct rethook_node *rh, void *data, struct kprobe_ctlblk *kcb; /* The data must NOT be null. This means rethook data structure is broken. */ - if (WARN_ON_ONCE(!data)) + if (WARN_ON_ONCE(!data) || !rp->handler) return; __this_cpu_write(current_kprobe, &rp->kp); |