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| author | Jackie Liu <liuyun01@kylinos.cn> | 2019-09-18 10:37:53 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-09-18 11:19:06 -0600 |
| commit | 5f5ad9ced33621d353be6429c3900f8a526fcae8 (patch) | |
| tree | 61705cf47d7f410ec0ef56c550c12462e92a9d60 /fs/io_uring.c | |
| parent | 954dab193d19cbbff8f83b58c9360bf00ddb273c (diff) | |
| download | lwn-5f5ad9ced33621d353be6429c3900f8a526fcae8.tar.gz lwn-5f5ad9ced33621d353be6429c3900f8a526fcae8.zip | |
io_uring: fix use-after-free of shadow_req
There is a potential dangling pointer problem. we never clean
shadow_req, if there are multiple link lists in this series of
sqes, then the shadow_req will not reallocate, and continue to
use the last one. but in the previous, his memory has been
released, thus forming a dangling pointer. let's clean up him
and make sure that every new link list can reapply for a new
shadow_req.
Fixes: 4fe2c963154c ("io_uring: add support for link with drain")
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/io_uring.c')
| -rw-r--r-- | fs/io_uring.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 42a684ef578a..1621243da1ea 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2357,6 +2357,7 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, struct sqe_submit *sqes, io_queue_link_head(ctx, link, &link->submit, shadow_req, true); link = NULL; + shadow_req = NULL; } prev_was_link = (sqes[i].sqe->flags & IOSQE_IO_LINK) != 0; @@ -2543,6 +2544,7 @@ static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit, io_queue_link_head(ctx, link, &link->submit, shadow_req, force_nonblock); link = NULL; + shadow_req = NULL; } prev_was_link = (s.sqe->flags & IOSQE_IO_LINK) != 0; |