[PATCH openEuler-5.10 1/2] net/x25: Fix null-ptr-deref caused by x25_disconnect
From: Duoming Zhou <duoming@zju.edu.cn> stable inclusion from stable-v5.10.110 commit 5c94b6205e87411dbe9dc1ca088eb36b8837fb47 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5661B CVE: CVE-2022-1516 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 7781607938c8371d4c2b243527430241c62e39c2 ] When the link layer is terminating, x25->neighbour will be set to NULL in x25_disconnect(). As a result, it could cause null-ptr-deref bugs in x25_sendmsg(),x25_recvmsg() and x25_connect(). One of the bugs is shown below. (Thread 1) | (Thread 2) x25_link_terminated() | x25_recvmsg() x25_kill_by_neigh() | ... x25_disconnect() | lock_sock(sk) ... | ... x25->neighbour = NULL //(1) | ... | x25->neighbour->extended //(2) The code sets NULL to x25->neighbour in position (1) and dereferences x25->neighbour in position (2), which could cause null-ptr-deref bug. This patch adds lock_sock() in x25_kill_by_neigh() in order to synchronize with x25_sendmsg(), x25_recvmsg() and x25_connect(). What`s more, the sock held by lock_sock() is not NULL, because it is extracted from x25_list and uses x25_list_lock to synchronize. Fixes: 4becb7ee5b3d ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Reviewed-by: Lin Ma <linma@zju.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Baisong Zhong <zhongbaisong@huawei.com> Reviewed-by: Yue Haibing <yuehaibing@huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- net/x25/af_x25.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index 03ed170b8125..d231d4620c38 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -1775,10 +1775,15 @@ void x25_kill_by_neigh(struct x25_neigh *nb) write_lock_bh(&x25_list_lock); - sk_for_each(s, &x25_list) - if (x25_sk(s)->neighbour == nb) + sk_for_each(s, &x25_list) { + if (x25_sk(s)->neighbour == nb) { + write_unlock_bh(&x25_list_lock); + lock_sock(s); x25_disconnect(s, ENETUNREACH, 0, 0); - + release_sock(s); + write_lock_bh(&x25_list_lock); + } + } write_unlock_bh(&x25_list_lock); /* Remove any related forwards */ -- 2.20.1
From: Jens Axboe <axboe@kernel.dk> stable inclusion from stable-v5.10.110 commit 2827328e646d0c2d3db1bfcad4b5f5016ce0d643 category: bugfix bugzilla: 186670, https://gitee.com/src-openeuler/kernel/issues/I54H78 CVE: CVE-2022-29582 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=l... -------------------------------- commit e677edbcabee849bfdd43f1602bccbecf736a646 upstream. io_flush_timeouts() assumes the timeout isn't in progress of triggering or being removed/canceled, so it unconditionally removes it from the timeout list and attempts to cancel it. Leave it on the list and let the normal timeout cancelation take care of it. Cc: stable@vger.kernel.org # 5.5+ Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Conflicts: fs/io_uring.c Signed-off-by: Guo Xuenan <guoxuenan@huawei.com> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- fs/io_uring.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index af6a1858c791..26a925d90074 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1556,6 +1556,7 @@ static void __io_queue_deferred(struct io_ring_ctx *ctx) static void io_flush_timeouts(struct io_ring_ctx *ctx) { + struct io_kiocb *req, *tmp; u32 seq; if (list_empty(&ctx->timeout_list)) @@ -1563,10 +1564,8 @@ static void io_flush_timeouts(struct io_ring_ctx *ctx) seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts); - do { + list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) { u32 events_needed, events_got; - struct io_kiocb *req = list_first_entry(&ctx->timeout_list, - struct io_kiocb, timeout.list); if (io_is_timeout_noseq(req)) break; @@ -1583,9 +1582,8 @@ static void io_flush_timeouts(struct io_ring_ctx *ctx) if (events_got < events_needed) break; - list_del_init(&req->timeout.list); io_kill_timeout(req, 0); - } while (!list_empty(&ctx->timeout_list)); + } ctx->cq_last_tm_flush = seq; } @@ -5629,6 +5627,7 @@ static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, else data->mode = HRTIMER_MODE_REL; + INIT_LIST_HEAD(&req->timeout.list); hrtimer_init(&data->timer, CLOCK_MONOTONIC, data->mode); return 0; } @@ -6281,6 +6280,7 @@ static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer) prev = NULL; } + list_del(&req->timeout.list); spin_unlock_irqrestore(&ctx->completion_lock, flags); if (prev) { -- 2.20.1
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Zheng Zengkai