diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-04 16:03:46 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-04 16:03:46 -0800 |
commit | ac84e82f78cb55ce8e760e0b5887d56efd78d6bc (patch) | |
tree | e55e804fb07bbd3e5db26d930663237e28c35d45 | |
parent | 07ebd38a0da24d2534da57b4841346379db9f354 (diff) | |
parent | 30939293262eb433c960c4532a0d59c4073b2b84 (diff) |
Merge tag 'block-5.17-2022-03-04' of git://git.kernel.dk/linux-block
Pull block fix from Jens Axboe:
"Just a small UAF fix for blktrace"
* tag 'block-5.17-2022-03-04' of git://git.kernel.dk/linux-block:
blktrace: fix use after free for struct blk_trace
-rw-r--r-- | kernel/trace/blktrace.c | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index af68a67179b4..21dea90eaa93 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -310,10 +310,20 @@ record_it: local_irq_restore(flags); } -static void blk_trace_free(struct blk_trace *bt) +static void blk_trace_free(struct request_queue *q, struct blk_trace *bt) { relay_close(bt->rchan); - debugfs_remove(bt->dir); + + /* + * If 'bt->dir' is not set, then both 'dropped' and 'msg' are created + * under 'q->debugfs_dir', thus lookup and remove them. + */ + if (!bt->dir) { + debugfs_remove(debugfs_lookup("dropped", q->debugfs_dir)); + debugfs_remove(debugfs_lookup("msg", q->debugfs_dir)); + } else { + debugfs_remove(bt->dir); + } free_percpu(bt->sequence); free_percpu(bt->msg_data); kfree(bt); @@ -335,10 +345,10 @@ static void put_probe_ref(void) mutex_unlock(&blk_probe_mutex); } -static void blk_trace_cleanup(struct blk_trace *bt) +static void blk_trace_cleanup(struct request_queue *q, struct blk_trace *bt) { synchronize_rcu(); - blk_trace_free(bt); + blk_trace_free(q, bt); put_probe_ref(); } @@ -352,7 +362,7 @@ static int __blk_trace_remove(struct request_queue *q) return -EINVAL; if (bt->trace_state != Blktrace_running) - blk_trace_cleanup(bt); + blk_trace_cleanup(q, bt); return 0; } @@ -572,7 +582,7 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, ret = 0; err: if (ret) - blk_trace_free(bt); + blk_trace_free(q, bt); return ret; } @@ -1616,7 +1626,7 @@ static int blk_trace_remove_queue(struct request_queue *q) put_probe_ref(); synchronize_rcu(); - blk_trace_free(bt); + blk_trace_free(q, bt); return 0; } @@ -1647,7 +1657,7 @@ static int blk_trace_setup_queue(struct request_queue *q, return 0; free_bt: - blk_trace_free(bt); + blk_trace_free(q, bt); return ret; } |