kernel/linux.git/net/netrom, branch v6.6.132

netrom: fix double-free in nr_route_frame()

2026-01-30T09:27:40+00:00

commit ba1096c315283ee3292765f6aea4cca15816c4f7 upstream. In nr_route_frame(), old_skb is immediately freed without checking if nr_neigh->ax25 pointer is NULL. Therefore, if nr_neigh->ax25 is NULL, the caller function will free old_skb again, causing a double-free bug. Therefore, to prevent this, we need to modify it to check whether nr_neigh->ax25 is NULL before freeing old_skb. Cc: Reported-by: syzbot+999115c3bf275797dc27@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/69694d6f.050a0220.58bed.0029.GAE@google.com/ Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Jeongjun Park Link: https://patch.msgid.link/20260119063359.10604-1-aha310510@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

netrom: Fix memory leak in nr_sendmsg()

2026-01-11T14:21:45+00:00

[ Upstream commit 613d12dd794e078be8ff3cf6b62a6b9acf7f4619 ] syzbot reported a memory leak [1]. When function sock_alloc_send_skb() return NULL in nr_output(), the original skb is not freed, which was allocated in nr_sendmsg(). Fix this by freeing it before return. [1] BUG: memory leak unreferenced object 0xffff888129f35500 (size 240): comm "syz.0.17", pid 6119, jiffies 4294944652 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 10 52 28 81 88 ff ff ..........R(.... backtrace (crc 1456a3e4): kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline] slab_post_alloc_hook mm/slub.c:4983 [inline] slab_alloc_node mm/slub.c:5288 [inline] kmem_cache_alloc_node_noprof+0x36f/0x5e0 mm/slub.c:5340 __alloc_skb+0x203/0x240 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0x69/0x3f0 net/core/skbuff.c:6671 sock_alloc_send_pskb+0x379/0x3e0 net/core/sock.c:2965 sock_alloc_send_skb include/net/sock.h:1859 [inline] nr_sendmsg+0x287/0x450 net/netrom/af_netrom.c:1105 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] sock_write_iter+0x293/0x2a0 net/socket.c:1195 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x45d/0x710 fs/read_write.c:686 ksys_write+0x143/0x170 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Reported-by: syzbot+d7abc36bbbb6d7d40b58@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d7abc36bbbb6d7d40b58 Tested-by: syzbot+d7abc36bbbb6d7d40b58@syzkaller.appspotmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Wang Liang Link: https://patch.msgid.link/20251129041315.1550766-1-wangliang74@huawei.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

netrom: check buffer length before accessing it

2025-01-09T12:32:00+00:00

[ Upstream commit a4fd163aed2edd967a244499754dec991d8b4c7d ] Syzkaller reports an uninit value read from ax25cmp when sending raw message through ieee802154 implementation. ===================================================== BUG: KMSAN: uninit-value in ax25cmp+0x3a5/0x460 net/ax25/ax25_addr.c:119 ax25cmp+0x3a5/0x460 net/ax25/ax25_addr.c:119 nr_dev_get+0x20e/0x450 net/netrom/nr_route.c:601 nr_route_frame+0x1a2/0xfc0 net/netrom/nr_route.c:774 nr_xmit+0x5a/0x1c0 net/netrom/nr_dev.c:144 __netdev_start_xmit include/linux/netdevice.h:4940 [inline] netdev_start_xmit include/linux/netdevice.h:4954 [inline] xmit_one net/core/dev.c:3548 [inline] dev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3564 __dev_queue_xmit+0x33b8/0x5130 net/core/dev.c:4349 dev_queue_xmit include/linux/netdevice.h:3134 [inline] raw_sendmsg+0x654/0xc10 net/ieee802154/socket.c:299 ieee802154_sock_sendmsg+0x91/0xc0 net/ieee802154/socket.c:96 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638 __sys_sendmsg net/socket.c:2667 [inline] __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x307/0x490 net/socket.c:2674 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Uninit was created at: slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x5e9/0xb10 mm/slub.c:3523 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560 __alloc_skb+0x318/0x740 net/core/skbuff.c:651 alloc_skb include/linux/skbuff.h:1286 [inline] alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6334 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2780 sock_alloc_send_skb include/net/sock.h:1884 [inline] raw_sendmsg+0x36d/0xc10 net/ieee802154/socket.c:282 ieee802154_sock_sendmsg+0x91/0xc0 net/ieee802154/socket.c:96 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638 __sys_sendmsg net/socket.c:2667 [inline] __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x307/0x490 net/socket.c:2674 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b CPU: 0 PID: 5037 Comm: syz-executor166 Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 ===================================================== This issue occurs because the skb buffer is too small, and it's actual allocation is aligned. This hides an actual issue, which is that nr_route_frame does not validate the buffer size before using it. Fix this issue by checking skb->len before accessing any fields in skb->data. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Co-developed-by: Nikita Marushkin Signed-off-by: Nikita Marushkin Signed-off-by: Ilya Shchipletsov Link: https://patch.msgid.link/20241219082308.3942-1-rabbelkin@mail.ru Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netrom: Fix a memory leak in nr_heartbeat_expiry()

2024-06-27T11:49:06+00:00

[ Upstream commit 0b9130247f3b6a1122478471ff0e014ea96bb735 ] syzbot reported a memory leak in nr_create() [0]. Commit 409db27e3a2e ("netrom: Fix use-after-free of a listening socket.") added sock_hold() to the nr_heartbeat_expiry() function, where a) a socket has a SOCK_DESTROY flag or b) a listening socket has a SOCK_DEAD flag. But in the case "a," when the SOCK_DESTROY flag is set, the file descriptor has already been closed and the nr_release() function has been called. So it makes no sense to hold the reference count because no one will call another nr_destroy_socket() and put it as in the case "b." nr_connect nr_establish_data_link nr_start_heartbeat nr_release switch (nr->state) case NR_STATE_3 nr->state = NR_STATE_2 sock_set_flag(sk, SOCK_DESTROY); nr_rx_frame nr_process_rx_frame switch (nr->state) case NR_STATE_2 nr_state2_machine() nr_disconnect() nr_sk(sk)->state = NR_STATE_0 sock_set_flag(sk, SOCK_DEAD) nr_heartbeat_expiry switch (nr->state) case NR_STATE_0 if (sock_flag(sk, SOCK_DESTROY) || (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD))) sock_hold() // ( !!! ) nr_destroy_socket() To fix the memory leak, let's call sock_hold() only for a listening socket. Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with Syzkaller. [0]: https://syzkaller.appspot.com/bug?extid=d327a1f3b12e1e206c16 Reported-by: syzbot+d327a1f3b12e1e206c16@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d327a1f3b12e1e206c16 Fixes: 409db27e3a2e ("netrom: Fix use-after-free of a listening socket.") Signed-off-by: Gavrilov Ilia Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

netrom: fix possible dead-lock in nr_rt_ioctl()

2024-06-12T09:12:12+00:00

[ Upstream commit e03e7f20ebf7e1611d40d1fdc1bde900fd3335f6 ] syzbot loves netrom, and found a possible deadlock in nr_rt_ioctl [1] Make sure we always acquire nr_node_list_lock before nr_node_lock(nr_node) [1] WARNING: possible circular locking dependency detected 6.9.0-rc7-syzkaller-02147-g654de42f3fc6 #0 Not tainted ------------------------------------------------------ syz-executor350/5129 is trying to acquire lock: ffff8880186e2070 (&nr_node->node_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff8880186e2070 (&nr_node->node_lock){+...}-{2:2}, at: nr_node_lock include/net/netrom.h:152 [inline] ffff8880186e2070 (&nr_node->node_lock){+...}-{2:2}, at: nr_dec_obs net/netrom/nr_route.c:464 [inline] ffff8880186e2070 (&nr_node->node_lock){+...}-{2:2}, at: nr_rt_ioctl+0x1bb/0x1090 net/netrom/nr_route.c:697 but task is already holding lock: ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: nr_dec_obs net/netrom/nr_route.c:462 [inline] ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: nr_rt_ioctl+0x10a/0x1090 net/netrom/nr_route.c:697 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (nr_node_list_lock){+...}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] nr_remove_node net/netrom/nr_route.c:299 [inline] nr_del_node+0x4b4/0x820 net/netrom/nr_route.c:355 nr_rt_ioctl+0xa95/0x1090 net/netrom/nr_route.c:683 sock_do_ioctl+0x158/0x460 net/socket.c:1222 sock_ioctl+0x629/0x8e0 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&nr_node->node_lock){+...}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] nr_node_lock include/net/netrom.h:152 [inline] nr_dec_obs net/netrom/nr_route.c:464 [inline] nr_rt_ioctl+0x1bb/0x1090 net/netrom/nr_route.c:697 sock_do_ioctl+0x158/0x460 net/socket.c:1222 sock_ioctl+0x629/0x8e0 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(nr_node_list_lock); lock(&nr_node->node_lock); lock(nr_node_list_lock); lock(&nr_node->node_lock); *** DEADLOCK *** 1 lock held by syz-executor350/5129: #0: ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #0: ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: nr_dec_obs net/netrom/nr_route.c:462 [inline] #0: ffffffff8f7053b8 (nr_node_list_lock){+...}-{2:2}, at: nr_rt_ioctl+0x10a/0x1090 net/netrom/nr_route.c:697 stack backtrace: CPU: 0 PID: 5129 Comm: syz-executor350 Not tainted 6.9.0-rc7-syzkaller-02147-g654de42f3fc6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] nr_node_lock include/net/netrom.h:152 [inline] nr_dec_obs net/netrom/nr_route.c:464 [inline] nr_rt_ioctl+0x1bb/0x1090 net/netrom/nr_route.c:697 sock_do_ioctl+0x158/0x460 net/socket.c:1222 sock_ioctl+0x629/0x8e0 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot Signed-off-by: Eric Dumazet Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20240515142934.3708038-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netrom: Fix data-races around sysctl_net_busy_read

2024-03-15T14:48:21+00:00

[ Upstream commit d380ce70058a4ccddc3e5f5c2063165dc07672c6 ] We need to protect the reader reading the sysctl value because the value can be changed concurrently. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Jason Xing Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

netrom: Fix a data-race around sysctl_netrom_link_fails_count

2024-03-15T14:48:20+00:00

[ Upstream commit bc76645ebdd01be9b9994dac39685a3d0f6f7985 ] We need to protect the reader reading the sysctl value because the value can be changed concurrently. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Jason Xing Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

netrom: Fix a data-race around sysctl_netrom_routing_control

2024-03-15T14:48:20+00:00

[ Upstream commit b5dffcb8f71bdd02a4e5799985b51b12f4eeaf76 ] We need to protect the reader reading the sysctl value because the value can be changed concurrently. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Jason Xing Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

netrom: Fix a data-race around sysctl_netrom_transport_no_activity_timeout

2024-03-15T14:48:20+00:00

[ Upstream commit f99b494b40431f0ca416859f2345746199398e2b ] We need to protect the reader reading the sysctl value because the value can be changed concurrently. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Jason Xing Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

netrom: Fix a data-race around sysctl_netrom_transport_requested_window_size

2024-03-15T14:48:20+00:00

[ Upstream commit a2e706841488f474c06e9b33f71afc947fb3bf56 ] We need to protect the reader reading the sysctl value because the value can be changed concurrently. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Jason Xing Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin