kernel.git/net/unix, branch linux-6.15.y

af_unix: Don't set -ECONNRESET for consumed OOB skb.

2025-07-06T09:04:15Z

[ Upstream commit 2a5a4841846b079b5fca5752fe94e59346fbda40 ] Christian Brauner reported that even after MSG_OOB data is consumed, calling close() on the receiver socket causes the peer's recv() to return -ECONNRESET: 1. send() and recv() an OOB data. >>> from socket import * >>> s1, s2 = socketpair(AF_UNIX, SOCK_STREAM) >>> s1.send(b'x', MSG_OOB) 1 >>> s2.recv(1, MSG_OOB) b'x' 2. close() for s2 sets ECONNRESET to s1->sk_err even though s2 consumed the OOB data >>> s2.close() >>> s1.recv(10, MSG_DONTWAIT) ... ConnectionResetError: [Errno 104] Connection reset by peer Even after being consumed, the skb holding the OOB 1-byte data stays in the recv queue to mark the OOB boundary and break recv() at that point. This must be considered while close()ing a socket. Let's skip the leading consumed OOB skb while checking the -ECONNRESET condition in unix_release_sock(). Fixes: 314001f0bf92 ("af_unix: Add OOB support") Reported-by: Christian Brauner Closes: https://lore.kernel.org/netdev/20250529-sinkt-abfeuern-e7b08200c6b0@brauner/ Signed-off-by: Kuniyuki Iwashima Acked-by: Christian Brauner Link: https://patch.msgid.link/20250619041457.1132791-4-kuni1840@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

af_unix: Don't leave consecutive consumed OOB skbs.

2025-07-06T09:04:11Z

[ Upstream commit 32ca245464e1479bfea8592b9db227fdc1641705 ] Jann Horn reported a use-after-free in unix_stream_read_generic(). The following sequences reproduce the issue: $ python3 from socket import * s1, s2 = socketpair(AF_UNIX, SOCK_STREAM) s1.send(b'x', MSG_OOB) s2.recv(1, MSG_OOB) # leave a consumed OOB skb s1.send(b'y', MSG_OOB) s2.recv(1, MSG_OOB) # leave a consumed OOB skb s1.send(b'z', MSG_OOB) s2.recv(1) # recv 'z' illegally s2.recv(1, MSG_OOB) # access 'z' skb (use-after-free) Even though a user reads OOB data, the skb holding the data stays on the recv queue to mark the OOB boundary and break the next recv(). After the last send() in the scenario above, the sk2's recv queue has 2 leading consumed OOB skbs and 1 real OOB skb. Then, the following happens during the next recv() without MSG_OOB 1. unix_stream_read_generic() peeks the first consumed OOB skb 2. manage_oob() returns the next consumed OOB skb 3. unix_stream_read_generic() fetches the next not-yet-consumed OOB skb 4. unix_stream_read_generic() reads and frees the OOB skb , and the last recv(MSG_OOB) triggers KASAN splat. The 3. above occurs because of the SO_PEEK_OFF code, which does not expect unix_skb_len(skb) to be 0, but this is true for such consumed OOB skbs. while (skip >= unix_skb_len(skb)) { skip -= unix_skb_len(skb); skb = skb_peek_next(skb, &sk->sk_receive_queue); ... } In addition to this use-after-free, there is another issue that ioctl(SIOCATMARK) does not function properly with consecutive consumed OOB skbs. So, nothing good comes out of such a situation. Instead of complicating manage_oob(), ioctl() handling, and the next ECONNRESET fix by introducing a loop for consecutive consumed OOB skbs, let's not leave such consecutive OOB unnecessarily. Now, while receiving an OOB skb in unix_stream_recv_urg(), if its previous skb is a consumed OOB skb, it is freed. [0]: BUG: KASAN: slab-use-after-free in unix_stream_read_actor (net/unix/af_unix.c:3027) Read of size 4 at addr ffff888106ef2904 by task python3/315 CPU: 2 UID: 0 PID: 315 Comm: python3 Not tainted 6.16.0-rc1-00407-gec315832f6f9 #8 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-4.fc42 04/01/2014 Call Trace: dump_stack_lvl (lib/dump_stack.c:122) print_report (mm/kasan/report.c:409 mm/kasan/report.c:521) kasan_report (mm/kasan/report.c:636) unix_stream_read_actor (net/unix/af_unix.c:3027) unix_stream_read_generic (net/unix/af_unix.c:2708 net/unix/af_unix.c:2847) unix_stream_recvmsg (net/unix/af_unix.c:3048) sock_recvmsg (net/socket.c:1063 (discriminator 20) net/socket.c:1085 (discriminator 20)) __sys_recvfrom (net/socket.c:2278) __x64_sys_recvfrom (net/socket.c:2291 (discriminator 1) net/socket.c:2287 (discriminator 1) net/socket.c:2287 (discriminator 1)) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) RIP: 0033:0x7f8911fcea06 Code: 5d e8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 75 19 83 e2 39 83 fa 08 75 11 e8 26 ff ff ff 66 0f 1f 44 00 00 48 8b 45 10 0f 05 <48> 8b 5d f8 c9 c3 0f 1f 40 00 f3 0f 1e fa 55 48 89 e5 48 83 ec 08 RSP: 002b:00007fffdb0dccb0 EFLAGS: 00000202 ORIG_RAX: 000000000000002d RAX: ffffffffffffffda RBX: 00007fffdb0dcdc8 RCX: 00007f8911fcea06 RDX: 0000000000000001 RSI: 00007f8911a5e060 RDI: 0000000000000006 RBP: 00007fffdb0dccd0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000202 R12: 00007f89119a7d20 R13: ffffffffc4653600 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 315: kasan_save_stack (mm/kasan/common.c:48) kasan_save_track (mm/kasan/common.c:60 (discriminator 1) mm/kasan/common.c:69 (discriminator 1)) __kasan_slab_alloc (mm/kasan/common.c:348) kmem_cache_alloc_node_noprof (./include/linux/kasan.h:250 mm/slub.c:4148 mm/slub.c:4197 mm/slub.c:4249) __alloc_skb (net/core/skbuff.c:660 (discriminator 4)) alloc_skb_with_frags (./include/linux/skbuff.h:1336 net/core/skbuff.c:6668) sock_alloc_send_pskb (net/core/sock.c:2993) unix_stream_sendmsg (./include/net/sock.h:1847 net/unix/af_unix.c:2256 net/unix/af_unix.c:2418) __sys_sendto (net/socket.c:712 (discriminator 20) net/socket.c:727 (discriminator 20) net/socket.c:2226 (discriminator 20)) __x64_sys_sendto (net/socket.c:2233 (discriminator 1) net/socket.c:2229 (discriminator 1) net/socket.c:2229 (discriminator 1)) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Freed by task 315: kasan_save_stack (mm/kasan/common.c:48) kasan_save_track (mm/kasan/common.c:60 (discriminator 1) mm/kasan/common.c:69 (discriminator 1)) kasan_save_free_info (mm/kasan/generic.c:579 (discriminator 1)) __kasan_slab_free (mm/kasan/common.c:271) kmem_cache_free (mm/slub.c:4643 (discriminator 3) mm/slub.c:4745 (discriminator 3)) unix_stream_read_generic (net/unix/af_unix.c:3010) unix_stream_recvmsg (net/unix/af_unix.c:3048) sock_recvmsg (net/socket.c:1063 (discriminator 20) net/socket.c:1085 (discriminator 20)) __sys_recvfrom (net/socket.c:2278) __x64_sys_recvfrom (net/socket.c:2291 (discriminator 1) net/socket.c:2287 (discriminator 1) net/socket.c:2287 (discriminator 1)) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) The buggy address belongs to the object at ffff888106ef28c0 which belongs to the cache skbuff_head_cache of size 224 The buggy address is located 68 bytes inside of freed 224-byte region [ffff888106ef28c0, ffff888106ef29a0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888106ef3cc0 pfn:0x106ef2 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x200000000000040(head|node=0|zone=2) page_type: f5(slab) raw: 0200000000000040 ffff8881001d28c0 ffffea000422fe00 0000000000000004 raw: ffff888106ef3cc0 0000000080190010 00000000f5000000 0000000000000000 head: 0200000000000040 ffff8881001d28c0 ffffea000422fe00 0000000000000004 head: ffff888106ef3cc0 0000000080190010 00000000f5000000 0000000000000000 head: 0200000000000001 ffffea00041bbc81 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888106ef2800: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ffff888106ef2880: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff888106ef2900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888106ef2980: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ffff888106ef2a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 314001f0bf92 ("af_unix: Add OOB support") Reported-by: Jann Horn Signed-off-by: Kuniyuki Iwashima Reviewed-by: Jann Horn Link: https://patch.msgid.link/20250619041457.1132791-2-kuni1840@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

unix: fix up for "apparmor: add fine grained af_unix mediation"

2025-03-26T16:31:18Z

After merging the apparmor tree, today's linux-next build (x86_64 allmodconfig) failed like this: security/apparmor/af_unix.c: In function 'unix_state_double_lock': security/apparmor/af_unix.c:627:17: error: implicit declaration of function 'unix_state_lock'; did you mean 'unix_state_double_lock'? [-Wimplicit-function-declaration] 627 | unix_state_lock(sk1); | ^~~~~~~~~~~~~~~ | unix_state_double_lock security/apparmor/af_unix.c: In function 'unix_state_double_unlock': security/apparmor/af_unix.c:642:17: error: implicit declaration of function 'unix_state_unlock'; did you mean 'unix_state_double_lock'? [-Wimplicit-function-declaration] 642 | unix_state_unlock(sk1); | ^~~~~~~~~~~~~~~~~ | unix_state_double_lock Caused by commit c05e705812d1 ("apparmor: add fine grained af_unix mediation") interacting with commit 84960bf24031 ("af_unix: Move internal definitions to net/unix/.") from the net-next tree. Reviewed-by: Kuniyuki Iwashima Signed-off-by: Stephen Rothwell Link: https://patch.msgid.link/20250326150148.72d9138d@canb.auug.org.au Signed-off-by: Jakub Kicinski

af_unix: Clean up #include under net/unix/.

2025-03-25T11:30:07Z

net/unix/*.c include many unnecessary header files (rtnetlink.h, netdevice.h, etc). Let's clean them up. af_unix.c: +uapi/linux/sockios.h : Only exist under include/uapi +uapi/linux/termios.h : Only exist under include/uapi -linux/freezer.h : No longer use freezable_schedule_timeout() -linux/in.h : No ipv4_is_XXX() etc -linux/module.h : No longer support CONFIG_UNIX=m -linux/netdevice.h : No dev used -linux/rtnetlink.h : Not part of rtnetlink API -linux/signal.h : signal_pending() is defined in sched/signal.h -linux/stat.h : No struct stat used -net/checksum.h : CHECKSUM_UNNECESSARY is defined in skbuff.h diag.c: +linux/dcache.h : struct dentry in sk_diag_dump_vfs() +linux/user_namespace.h : struct user_namespace in sk_diag_dump_uid() +uapi/linux/unix_diag.h : Only exist under include/uapi/ garbage.c: +linux/list.h : struct unix_{vertex,edge}, etc +linux/workqueue.h : DECLARE_WORK(unix_gc_work, ...) -linux/file.h : No fget() etc -linux/kernel.h : No cond_resched() etc -linux/netdevice.h : No dev used -linux/proc_fs.h : No procfs provided -linux/string.h : No memcpy(), kmemdup(), etc sysctl_net_unix.c: +linux/string.h : kmemdup() +net/net_namespace.h : struct net, net_eq() -linux/mm.h : slab.h is enough Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250318034934.86708-5-kuniyu@amazon.com Signed-off-by: Jakub Kicinski

af_unix: Explicitly include headers for non-pointer struct fields.

2025-03-25T11:30:07Z

include/net/af_unix.h indirectly includes some definitions for structs. Let's include such headers explicitly. linux/atomic.h : scm_stat.nr_fds linux/net.h : unix_sock.peer_wq linux/path.h : unix_sock.path linux/spinlock.h : unix_sock.lock linux/wait.h : unix_sock.peer_wake uapi/linux/un.h : unix_address.name[] linux/socket.h is removed as the structs there are not used directly, and linux/un.h is clarified with uapi as un.h only exists under include/uapi. While at it, duplicate headers are removed from .c files. Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250318034934.86708-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski

af_unix: Move internal definitions to net/unix/.

2025-03-25T11:30:07Z

net/af_unix.h is included by core and some LSMs, but most definitions need not be. Let's move struct unix_{vertex,edge} to net/unix/garbage.c and other definitions to net/unix/af_unix.h. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Joe Damato Link: https://patch.msgid.link/20250318034934.86708-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski

af_unix: Sort headers.

2025-03-25T11:30:07Z

This is a prep patch to make the following changes cleaner. No functional change intended. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Joe Damato Link: https://patch.msgid.link/20250318034934.86708-2-kuniyu@amazon.com Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2025-02-27T18:20:58Z

Cross-merge networking fixes after downstream PR (net-6.14-rc5). Conflicts: drivers/net/ethernet/cadence/macb_main.c fa52f15c745c ("net: cadence: macb: Synchronize stats calculations") 75696dd0fd72 ("net: cadence: macb: Convert to get_stats64") https://lore.kernel.org/20250224125848.68ee63e5@canb.auug.org.au Adjacent changes: drivers/net/ethernet/intel/ice/ice_sriov.c 79990cf5e7ad ("ice: Fix deinitializing VF in error path") a203163274a4 ("ice: simplify VF MSI-X managing") net/ipv4/tcp.c 18912c520674 ("tcp: devmem: don't write truncated dmabuf CMSGs to userspace") 297d389e9e5b ("net: prefix devmem specific helpers") net/mptcp/subflow.c 8668860b0ad3 ("mptcp: reset when MPTCP opts are dropped after join") c3349a22c200 ("mptcp: consolidate subflow cleanup") Signed-off-by: Jakub Kicinski

af_unix: Fix memory leak in unix_dgram_sendmsg()

2025-02-27T03:01:36Z

After running the 'sendmsg02' program of Linux Test Project (LTP), kmemleak reports the following memory leak: # cat /sys/kernel/debug/kmemleak unreferenced object 0xffff888243866800 (size 2048): comm "sendmsg02", pid 67, jiffies 4294903166 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 5e 00 00 00 00 00 00 00 ........^....... 01 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00 ...@............ backtrace (crc 7e96a3f2): kmemleak_alloc+0x56/0x90 kmem_cache_alloc_noprof+0x209/0x450 sk_prot_alloc.constprop.0+0x60/0x160 sk_alloc+0x32/0xc0 unix_create1+0x67/0x2b0 unix_create+0x47/0xa0 __sock_create+0x12e/0x200 __sys_socket+0x6d/0x100 __x64_sys_socket+0x1b/0x30 x64_sys_call+0x7e1/0x2140 do_syscall_64+0x54/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e Commit 689c398885cc ("af_unix: Defer sock_put() to clean up path in unix_dgram_sendmsg().") defers sock_put() in the error handling path. However, it fails to account for the condition 'msg->msg_namelen != 0', resulting in a memory leak when the code jumps to the 'lookup' label. Fix issue by calling sock_put() if 'msg->msg_namelen != 0' is met. Fixes: 689c398885cc ("af_unix: Defer sock_put() to clean up path in unix_dgram_sendmsg().") Signed-off-by: Adrian Huang Acked-by: Joe Damato Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250225021457.1824-1-ahuang12@lenovo.com Signed-off-by: Jakub Kicinski

af_unix: Fix undefined 'other' error

2025-02-20T23:28:46Z

Fix an issue with the sparse static analysis tool where an "undefined 'other'" error occurs due to `__releases(&unix_sk(other)->lock)` being placed before 'other' is in scope. Remove the `__releases()` annotation from the `unix_wait_for_peer()` function to eliminate the sparse error. The annotation references `other` before it is declared, leading to a false positive error during static analysis. Since AF_UNIX does not use sparse annotations, this annotation is unnecessary and does not impact functionality. Reviewed-by: Joe Damato Reviewed-by: Simon Horman Signed-off-by: Purva Yeshi Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250218141045.38947-1-purvayeshi550@gmail.com Signed-off-by: Jakub Kicinski