diff options
| author | Masami Hiramatsu <mhiramat@kernel.org> | 2021-12-01 23:45:50 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-08 09:01:10 +0100 |
| commit | c2e2ccaac3d9f31e711ac141f95fecf352cff4c2 (patch) | |
| tree | 017260f13a62aa9caf469d288c5089120c2a68c2 | |
| parent | 03ee5e8c63c3d0d5150699b570b6dcf74e2759b3 (diff) | |
kprobes: Limit max data_size of the kretprobe instances
commit 6bbfa44116689469267f1a6e3d233b52114139d2 upstream.
The 'kprobe::data_size' is unsigned, thus it can not be negative. But if
user sets it enough big number (e.g. (size_t)-8), the result of 'data_size
+ sizeof(struct kretprobe_instance)' becomes smaller than sizeof(struct
kretprobe_instance) or zero. In result, the kretprobe_instance are
allocated without enough memory, and kretprobe accesses outside of
allocated memory.
To avoid this issue, introduce a max limitation of the
kretprobe::data_size. 4KB per instance should be OK.
Link: https://lkml.kernel.org/r/163836995040.432120.10322772773821182925.stgit@devnote2
Cc: stable@vger.kernel.org
Fixes: f47cd9b553aa ("kprobes: kretprobe user entry-handler")
Reported-by: zhangyue <zhangyue1@kylinos.cn>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | include/linux/kprobes.h | 2 | ||||
| -rw-r--r-- | kernel/kprobes.c | 3 |
2 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index a121fd8e7c3a..c7764d9e6f39 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -155,6 +155,8 @@ struct kretprobe { raw_spinlock_t lock; }; +#define KRETPROBE_MAX_DATA_SIZE 4096 + struct kretprobe_instance { struct hlist_node hlist; struct kretprobe *rp; diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 1668439b269d..c93340bae3ac 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2003,6 +2003,9 @@ int register_kretprobe(struct kretprobe *rp) } } + if (rp->data_size > KRETPROBE_MAX_DATA_SIZE) + return -E2BIG; + rp->kp.pre_handler = pre_handler_kretprobe; rp->kp.post_handler = NULL; rp->kp.fault_handler = NULL; |