kernel/linux.git/net/x25, branch v6.12.101

net/x25: fix use-after-free in x25_kill_by_neigh()

2026-08-03T09:17:26+00:00

commit 5499e0602d2faafd42c580d25f615903c3fbe11b upstream. x25_kill_by_neigh() walks the global X.25 socket list looking for sockets attached to a terminating neighbour. x25_list_lock protects list membership while the lookup is in progress, but it does not pin a socket's lifetime after the lock is dropped. The function currently drops x25_list_lock before calling lock_sock(s). A concurrent close can run x25_release(), remove the same socket from x25_list, and drop the last socket reference in that window. The neighbour teardown path can then lock or inspect a freed struct sock/struct x25_sock. Take sock_hold(s) while x25_list_lock still proves that the list entry is live, then drop the temporary reference after the socket has been locked, rechecked, and released. Recheck x25_sk(s)->neighbour after lock_sock(), because another path may have disconnected the socket before this path acquired the socket lock. Restart the list walk after each disconnect because the list lock was dropped and the previous iterator state may no longer be valid. A QEMU/KASAN run against origin/master reproduced a slab-use-after-free in x25_kill_by_neigh(). Fixes: 7781607938c8 ("net/x25: Fix null-ptr-deref caused by x25_disconnect") Cc: stable@vger.kernel.org Signed-off-by: David Lee Assisted-by: Codex:gpt-5.5 Acked-by: Martin Schiller Link: https://patch.msgid.link/20260713104752.241175-1-david.lee@trailofbits.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

net/x25: Fix overflow when accumulating packets

2026-04-11T12:24:37+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

2026-04-11T12:24:37+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: change proto and proto_ops accept type

2024-05-14T00:19:09+00:00

Rather than pass in flags, error pointer, and whether this is a kernel invocation or not, add a struct proto_accept_arg struct as the argument. This then holds all of these arguments, and prepares accept for being able to pass back more information. No functional changes in this patch. Acked-by: Jakub Kicinski Signed-off-by: Jens Axboe

ax.25: x.25: Remove the now superfluous sentinel elements from ctl_table array

2024-05-03T12:29:43+00:00

This commit comes at the tail end of a greater effort to remove the empty elements at the end of the ctl_table arrays (sentinels) which will reduce the overall build time size of the kernel and run time memory bloat by ~64 bytes per sentinel (further information Link : https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/) Avoid a buffer overflow when traversing the ctl_table by ensuring that AX25_MAX_VALUES is the same as the size of ax25_param_table. This is done with a BUILD_BUG_ON where ax25_param_table is defined and a CONFIG_AX25_DAMA_SLAVE guard in the unnamed enum definition as well as in the ax25_dev_device_up and ax25_ds_set_timer functions. The overflow happened when the sentinel was removed from ax25_param_table. The sentinel's data element was changed when CONFIG_AX25_DAMA_SLAVE was undefined. This had no adverse effects as it still stopped on the sentinel's null procname but needed to be addressed once the sentinel was removed. Signed-off-by: Joel Granados Signed-off-by: David S. Miller

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

2024-03-11T09:53:22+00:00

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

net: x25: remove dead links from Kconfig

2024-03-08T04:24:35+00:00

Remove the "You can read more about X.25 at" links provided in Kconfig as they have not pointed at any relevant pages for quite a while. An old copy of https://www.sangoma.com/tutorials/x25/ can be retrieved via https://archive.org/web/ but nothing useful seems to have been preserved for http://docwiki.cisco.com/wiki/X.25 For the sake of necromancy and those who really did want to read more about X.25, a previous incarnation of Kconfig included a link to: http://www.cisco.com/univercd/cc/td/doc/product/software/ios11/cbook/cx25.htm Which can still be read at: https://web.archive.org/web/20071013101232/http://cisco.com/en/US/docs/ios/11_0/router/configuration/guide/cx25.html Signed-off-by: Justin Swartz Acked-by: Martin Schiller Link: https://lore.kernel.org/r/20240306112659.25375-1-justin.swartz@risingedge.co.za Signed-off-by: Jakub Kicinski

net: remove SOCK_DEBUG leftovers

2023-12-26T20:31:01+00:00

SOCK_DEBUG comes from the old days. Let's move logging to standard net core ratelimited logging functions Signed-off-by: Denis Kirjanov changes in v2: - remove SOCK_DEBUG macro altogether Signed-off-by: David S. Miller

net: implement lockless SO_PRIORITY

2023-10-01T18:09:54+00:00

This is a followup of 8bf43be799d4 ("net: annotate data-races around sk->sk_priority"). sk->sk_priority can be read and written without holding the socket lock. Signed-off-by: Eric Dumazet Reviewed-by: Wenjia Zhang Signed-off-by: David S. Miller

sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES)

2023-06-24T22:50:13+00:00

Remove ->sendpage() and ->sendpage_locked(). sendmsg() with MSG_SPLICE_PAGES should be used instead. This allows multiple pages and multipage folios to be passed through. Signed-off-by: David Howells Acked-by: Marc Kleine-Budde # for net/can cc: Jens Axboe cc: Matthew Wilcox cc: linux-afs@lists.infradead.org cc: mptcp@lists.linux.dev cc: rds-devel@oss.oracle.com cc: tipc-discussion@lists.sourceforge.net cc: virtualization@lists.linux-foundation.org Link: https://lore.kernel.org/r/20230623225513.2732256-16-dhowells@redhat.com Signed-off-by: Jakub Kicinski