Messages in this thread Patch in this message | | | From | Zhen Lei <> | Subject | [PATCH 1/2] pipe: fix potential use-after-free in pipe_read() | Date | Mon, 15 Nov 2021 11:57:20 +0800 |
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Accessing buf->flags after pipe_buf_release(pipe, buf) is unsafe, because the 'buf' memory maybe freed.
Fixes: e7d553d69cf6 ("pipe: Add notification lossage handling") Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> --- fs/pipe.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/pipe.c b/fs/pipe.c index 6d4342bad9f15b2..302f1e50ce3be1d 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -319,10 +319,12 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to) } if (!buf->len) { + unsigned int __maybe_unused flags = buf->flags; + pipe_buf_release(pipe, buf); spin_lock_irq(&pipe->rd_wait.lock); #ifdef CONFIG_WATCH_QUEUE - if (buf->flags & PIPE_BUF_FLAG_LOSS) + if (flags & PIPE_BUF_FLAG_LOSS) pipe->note_loss = true; #endif tail++; -- 2.26.0.106.g9fadedd
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