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authorJackie Liu <liuyun01@kylinos.cn>2019-09-18 10:37:53 +0800
committerJens Axboe <axboe@kernel.dk>2019-09-18 11:19:06 -0600
commit5f5ad9ced33621d353be6429c3900f8a526fcae8 (patch)
tree61705cf47d7f410ec0ef56c550c12462e92a9d60 /fs/io_uring.c
parent954dab193d19cbbff8f83b58c9360bf00ddb273c (diff)
downloadlinux-5f5ad9ced33621d353be6429c3900f8a526fcae8.tar.bz2
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.c2
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;