kernel/linux.git/net/x25, branch v5.10.257

net/x25: Fix overflow when accumulating packets

2026-04-18T08:31:10+00:00

[ Upstream commit a1822cb524e89b4cd2cf0b82e484a2335496a6d9 ] Add a check to ensure that `x25_sock.fraglen` does not overflow. The `fraglen` also needs to be resetted when purging `fragment_queue` in `x25_clear_queues()`. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Suggested-by: Yiming Qian Signed-off-by: Martin Schiller Link: https://patch.msgid.link/20260331-x25_fraglen-v4-2-3e69f18464b4@dev.tdt.de Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net/x25: Fix potential double free of skb

2026-04-18T08:31:10+00:00

[ Upstream commit d10a26aa4d072320530e6968ef945c8c575edf61 ] When alloc_skb fails in x25_queue_rx_frame it calls kfree_skb(skb) at line 48 and returns 1 (error). This error propagates back through the call chain: x25_queue_rx_frame returns 1 | v x25_state3_machine receives the return value 1 and takes the else branch at line 278, setting queued=0 and returning 0 | v x25_process_rx_frame returns queued=0 | v x25_backlog_rcv at line 452 sees queued=0 and calls kfree_skb(skb) again This would free the same skb twice. Looking at x25_backlog_rcv: net/x25/x25_in.c:x25_backlog_rcv() { ... queued = x25_process_rx_frame(sk, skb); ... if (!queued) kfree_skb(skb); } Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Martin Schiller Link: https://patch.msgid.link/20260331-x25_fraglen-v4-1-3e69f18464b4@dev.tdt.de Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net/x25: fix incorrect parameter validation in the x25_getsockopt() function

2024-03-26T22:21:54+00:00

[ Upstream commit d6eb8de2015f0c24822e47356f839167ebde2945 ] The 'len' variable can't be negative when assigned the result of 'min_t' because all 'min_t' parameters are cast to unsigned int, and then the minimum one is chosen. To fix the logic, check 'len' as read from 'optlen', where the types of relevant variables are (signed) int. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Gavrilov Ilia Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net/x25: Fix to not accept on connected socket

2023-02-15T16:22:15+00:00

[ Upstream commit f2b0b5210f67c56a3bcdf92ff665fb285d6e0067 ] When listen() and accept() are called on an x25 socket that connect() succeeds, accept() succeeds immediately. This is because x25_connect() queues the skb to sk->sk_receive_queue, and x25_accept() dequeues it. This creates a child socket with the sk of the parent x25 socket, which can cause confusion. Fix x25_listen() to return -EINVAL if the socket has already been successfully connect()ed to avoid this issue. Signed-off-by: Hyunwoo Kim Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net/x25: Fix skb leak in x25_lapb_receive_frame()

2022-11-25T16:45:47+00:00

[ Upstream commit 2929cceb2fcf0ded7182562e4888afafece82cce ] x25_lapb_receive_frame() using skb_copy() to get a private copy of skb, the new skb should be freed in the undersized/fragmented skb error handling path. Otherwise there is a memory leak. Fixes: cb101ed2c3c7 ("x25: Handle undersized/fragmented skbs") Signed-off-by: Wei Yongjun Acked-by: Martin Schiller Link: https://lore.kernel.org/r/20221114110519.514538-1-weiyongjun@huaweicloud.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net/x25: Fix null-ptr-deref caused by x25_disconnect

2022-04-08T12:40:30+00:00

[ 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 Reviewed-by: Lin Ma Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net/x25: Return the correct errno code

2021-06-18T08:00:06+00:00

[ Upstream commit d7736958668c4facc15f421e622ffd718f5be80a ] When kalloc or kmemdup failed, should return ENOMEM rather than ENOBUF. Signed-off-by: Zheng Yongjun Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net/x25: prevent a couple of overflows

2020-12-03T01:26:36+00:00

The .x25_addr[] address comes from the user and is not necessarily NUL terminated. This leads to a couple problems. The first problem is that the strlen() in x25_bind() can read beyond the end of the buffer. The second problem is more subtle and could result in memory corruption. The call tree is: x25_connect() --> x25_write_internal() --> x25_addr_aton() The .x25_addr[] buffers are copied to the "addresses" buffer from x25_write_internal() so it will lead to stack corruption. Verify that the strings are NUL terminated and return -EINVAL if they are not. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Fixes: a9288525d2ae ("X25: Dont let x25_bind use addresses containing characters") Reported-by: "kiyin(尹亮)" Signed-off-by: Dan Carpenter Acked-by: Martin Schiller Link: https://lore.kernel.org/r/X8ZeAKm8FnFpN//B@mwanda Signed-off-by: Jakub Kicinski

net: x25: Increase refcnt of "struct x25_neigh" in x25_rx_call_request

2020-11-13T02:01:40+00:00

The x25_disconnect function in x25_subr.c would decrease the refcount of "x25->neighbour" (struct x25_neigh) and reset this pointer to NULL. However, the x25_rx_call_request function in af_x25.c, which is called when we receive a connection request, does not increase the refcount when it assigns the pointer. Fix this issue by increasing the refcount of "struct x25_neigh" in x25_rx_call_request. This patch fixes frequent kernel crashes when using AF_X25 sockets. Fixes: 4becb7ee5b3d ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect") Cc: Martin Schiller Signed-off-by: Xie He Link: https://lore.kernel.org/r/20201112103506.5875-1-xie.he.0141@gmail.com Signed-off-by: Jakub Kicinski

net/x25: Fix null-ptr-deref in x25_connect

2020-11-11T22:53:56+00:00

This fixes a regression for blocking connects introduced by commit 4becb7ee5b3d ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect"). The x25->neighbour is already set to "NULL" by x25_disconnect() now, while a blocking connect is waiting in x25_wait_for_connection_establishment(). Therefore x25->neighbour must not be accessed here again and x25->state is also already set to X25_STATE_0 by x25_disconnect(). Fixes: 4becb7ee5b3d ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect") Signed-off-by: Martin Schiller Reviewed-by: Xie He Link: https://lore.kernel.org/r/20201109065449.9014-1-ms@dev.tdt.de Signed-off-by: Jakub Kicinski