From: Lee Jones lee@kernel.org
stable inclusion from stable-v5.10.134 commit 2ee0cab11f6626071f8a64c7792406dabdd94c8d category: bugfix bugzilla: 187845, https://gitee.com/src-openeuler/kernel/issues/I5UDNW CVE: CVE-2022-20409
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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This issue is conceptually identical to the one fixed in 29f077d07051 ("io_uring: always use original task when preparing req identity"), so rather than reinvent the wheel, I'm shamelessly quoting the commit message from that patch - thanks Jens:
"If the ring is setup with IORING_SETUP_IOPOLL and we have more than one task doing submissions on a ring, we can up in a situation where we assign the context from the current task rather than the request originator.
Always use req->task rather than assume it's the same as current.
No upstream patch exists for this issue, as only older kernels with the non-native workers have this problem."
Cc: Jens Axboe axboe@kernel.dk Cc: Pavel Begunkov asml.silence@gmail.com Cc: Alexander Viro viro@zeniv.linux.org.uk Cc: io-uring@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Fixes: 5c3462cfd123b ("io_uring: store io_identity in io_uring_task") Signed-off-by: Lee Jones lee@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Li Lingfeng lilingfeng3@huawei.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- fs/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c index 5a88260a8dd8..4e790ae69e68 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1325,7 +1325,7 @@ static void io_req_clean_work(struct io_kiocb *req) */ static bool io_identity_cow(struct io_kiocb *req) { - struct io_uring_task *tctx = current->io_uring; + struct io_uring_task *tctx = req->task->io_uring; const struct cred *creds = NULL; struct io_identity *id;