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| author | Adam Zabrocki <pi3@pi3.com.pl> | 2022-04-22 18:40:27 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2022-04-26 16:09:36 +0200 |
| commit | 1d661ed54d8613c97bcff2c7d6181c61e482a1da (patch) | |
| tree | f126c3bcc98255dfed064c1ac7a95fc58e771613 /kernel/kprobes.c | |
| parent | bpf, lwt: Fix crash when using bpf_skb_set_tunnel_key() from bpf_xmit lwt hook (diff) | |
| download | linux-1d661ed54d8613c97bcff2c7d6181c61e482a1da.tar.xz linux-1d661ed54d8613c97bcff2c7d6181c61e482a1da.zip | |
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 <pi3@pi3.com.pl>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Anil S. Keshavamurthy <anil.s.keshavamurthy@intel.com>
Link: https://lore.kernel.org/bpf/20220422164027.GA7862@pi3.com.pl
Diffstat (limited to 'kernel/kprobes.c')
| -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); |