kernel/linux.git/net/rose, branch v6.19.11

net/rose: fix NULL pointer dereference in rose_transmit_link on reconnect

2026-03-25T10:13:25+00:00

[ Upstream commit e1f0a18c9564cdb16523c802e2c6fe5874e3d944 ] syzkaller reported a bug [1], and the reproducer is available at [2]. ROSE sockets use four sk->sk_state values: TCP_CLOSE, TCP_LISTEN, TCP_SYN_SENT, and TCP_ESTABLISHED. rose_connect() already rejects calls for TCP_ESTABLISHED (-EISCONN) and TCP_CLOSE with SS_CONNECTING (-ECONNREFUSED), but lacks a check for TCP_SYN_SENT. When rose_connect() is called a second time while the first connection attempt is still in progress (TCP_SYN_SENT), it overwrites rose->neighbour via rose_get_neigh(). If that returns NULL, the socket is left with rose->state == ROSE_STATE_1 but rose->neighbour == NULL. When the socket is subsequently closed, rose_release() sees ROSE_STATE_1 and calls rose_write_internal() -> rose_transmit_link(skb, NULL), causing a NULL pointer dereference. Per connect(2), a second connect() while a connection is already in progress should return -EALREADY. Add this missing check for TCP_SYN_SENT to complete the state validation in rose_connect(). [1] https://syzkaller.appspot.com/bug?extid=d00f90e0af54102fb271 [2] https://gist.github.com/mrpre/9e6779e0d13e2c66779b1653fef80516 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+d00f90e0af54102fb271@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/69694d6f.050a0220.58bed.0027.GAE@google.com/T/ Suggested-by: Eric Dumazet Signed-off-by: Jiayuan Chen Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260311070611.76913-1-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: rose: fix invalid array index in rose_kill_by_device()

2025-12-30T10:45:51+00:00

rose_kill_by_device() collects sockets into a local array[] and then iterates over them to disconnect sockets bound to a device being brought down. The loop mistakenly indexes array[cnt] instead of array[i]. For cnt < ARRAY_SIZE(array), this reads an uninitialized entry; for cnt == ARRAY_SIZE(array), it is an out-of-bounds read. Either case can lead to an invalid socket pointer dereference and also leaks references taken via sock_hold(). Fix the index to use i. Fixes: 64b8bc7d5f143 ("net/rose: fix races in rose_kill_by_device()") Co-developed-by: Fatma Alwasmi Signed-off-by: Fatma Alwasmi Signed-off-by: Pwnverse Link: https://patch.msgid.link/20251222212227.4116041-1-ritviktanksalkar@gmail.com Signed-off-by: Paolo Abeni

net: Convert proto_ops connect() callbacks to use sockaddr_unsized

2025-11-05T03:10:32+00:00

Update all struct proto_ops connect() callback function prototypes from "struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the compiler about object sizes. Calls into struct proto handlers gain casts that will be removed in the struct proto conversion patch. No binary changes expected. Signed-off-by: Kees Cook Link: https://patch.msgid.link/20251104002617.2752303-3-kees@kernel.org Signed-off-by: Jakub Kicinski

net: Convert proto_ops bind() callbacks to use sockaddr_unsized

2025-11-05T03:10:32+00:00

Update all struct proto_ops bind() callback function prototypes from "struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the compiler about object sizes. Calls into struct proto handlers gain casts that will be removed in the struct proto conversion patch. No binary changes expected. Signed-off-by: Kees Cook Link: https://patch.msgid.link/20251104002617.2752303-2-kees@kernel.org Signed-off-by: Jakub Kicinski

net: rose: fix a typo in rose_clear_routes()

2025-08-28T00:27:52+00:00

syzbot crashed in rose_clear_routes(), after a recent patch typo. KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 0 UID: 0 PID: 10591 Comm: syz.3.1856 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:rose_clear_routes net/rose/rose_route.c:565 [inline] RIP: 0010:rose_rt_ioctl+0x162/0x1250 net/rose/rose_route.c:760 rose_ioctl+0x3ce/0x8b0 net/rose/af_rose.c:1381 sock_do_ioctl+0xd9/0x300 net/socket.c:1238 sock_ioctl+0x576/0x790 net/socket.c:1359 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: da9c9c877597 ("net: rose: include node references in rose_neigh refcount") Reported-by: syzbot+2eb8d1719f7cfcfa6840@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/68af3e29.a70a0220.3cafd4.002e.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Cc: Takamitsu Iwai Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250827172149.5359-1-edumazet@google.com Signed-off-by: Jakub Kicinski

net: rose: include node references in rose_neigh refcount

2025-08-27T14:43:09+00:00

Current implementation maintains two separate reference counting mechanisms: the 'count' field in struct rose_neigh tracks references from rose_node structures, while the 'use' field (now refcount_t) tracks references from rose_sock. This patch merges these two reference counting systems using 'use' field for proper reference management. Specifically, this patch adds incrementing and decrementing of rose_neigh->use when rose_neigh->count is incremented or decremented. This patch also modifies rose_rt_free(), rose_rt_device_down() and rose_clear_route() to properly release references to rose_neigh objects before freeing a rose_node through rose_remove_node(). These changes ensure rose_neigh structures are properly freed only when all references, including those from rose_node structures, are released. As a result, this resolves a slab-use-after-free issue reported by Syzbot. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+942297eecf7d2d61d1f1@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=942297eecf7d2d61d1f1 Signed-off-by: Takamitsu Iwai Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250823085857.47674-4-takamitz@amazon.co.jp Signed-off-by: Jakub Kicinski

net: rose: convert 'use' field to refcount_t

2025-08-27T14:43:08+00:00

The 'use' field in struct rose_neigh is used as a reference counter but lacks atomicity. This can lead to race conditions where a rose_neigh structure is freed while still being referenced by other code paths. For example, when rose_neigh->use becomes zero during an ioctl operation via rose_rt_ioctl(), the structure may be removed while its timer is still active, potentially causing use-after-free issues. This patch changes the type of 'use' from unsigned short to refcount_t and updates all code paths to use rose_neigh_hold() and rose_neigh_put() which operate reference counts atomically. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Takamitsu Iwai Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250823085857.47674-3-takamitz@amazon.co.jp Signed-off-by: Jakub Kicinski

net: rose: split remove and free operations in rose_remove_neigh()

2025-08-27T14:43:08+00:00

The current rose_remove_neigh() performs two distinct operations: 1. Removes rose_neigh from rose_neigh_list 2. Frees the rose_neigh structure Split these operations into separate functions to improve maintainability and prepare for upcoming refcount_t conversion. The timer cleanup remains in rose_remove_neigh() because free operations can be called from timer itself. This patch introduce rose_neigh_put() to handle the freeing of rose_neigh structures and modify rose_remove_neigh() to handle removal only. Signed-off-by: Takamitsu Iwai Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250823085857.47674-2-takamitz@amazon.co.jp Signed-off-by: Jakub Kicinski

net: track pfmemalloc drops via SKB_DROP_REASON_PFMEMALLOC

2025-07-18T23:59:05+00:00

Add a new SKB drop reason (SKB_DROP_REASON_PFMEMALLOC) to track packets dropped due to memory pressure. In production environments, we've observed memory exhaustion reported by memory layer stack traces, but these drops were not properly tracked in the SKB drop reason infrastructure. While most network code paths now properly report pfmemalloc drops, some protocol-specific socket implementations still use sk_filter() without drop reason tracking: - Bluetooth L2CAP sockets - CAIF sockets - IUCV sockets - Netlink sockets - SCTP sockets - Unix domain sockets These remaining cases represent less common paths and could be converted in a follow-up patch if needed. The current implementation provides significantly improved observability into memory pressure events in the network stack, especially for key protocols like TCP and UDP, helping to diagnose problems in production environments. Reported-by: Matt Fleming Signed-off-by: Jesper Dangaard Brouer Link: https://patch.msgid.link/175268316579.2407873.11634752355644843509.stgit@firesoul Signed-off-by: Jakub Kicinski

rose: fix dangling neighbour pointers in rose_rt_device_down()

2025-07-02T02:28:48+00:00

There are two bugs in rose_rt_device_down() that can cause use-after-free: 1. The loop bound `t->count` is modified within the loop, which can cause the loop to terminate early and miss some entries. 2. When removing an entry from the neighbour array, the subsequent entries are moved up to fill the gap, but the loop index `i` is still incremented, causing the next entry to be skipped. For example, if a node has three neighbours (A, A, B) with count=3 and A is being removed, the second A is not checked. i=0: (A, A, B) -> (A, B) with count=2 ^ checked i=1: (A, B) -> (A, B) with count=2 ^ checked (B, not A!) i=2: (doesn't occur because i < count is false) This leaves the second A in the array with count=2, but the rose_neigh structure has been freed. Code that accesses these entries assumes that the first `count` entries are valid pointers, causing a use-after-free when it accesses the dangling pointer. Fix both issues by iterating over the array in reverse order with a fixed loop bound. This ensures that all entries are examined and that the removal of an entry doesn't affect subsequent iterations. Reported-by: syzbot+e04e2c007ba2c80476cb@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=e04e2c007ba2c80476cb Tested-by: syzbot+e04e2c007ba2c80476cb@syzkaller.appspotmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kohei Enju Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250629030833.6680-1-enjuk@amazon.com Signed-off-by: Jakub Kicinski