kernel/linux.git/net/core/sock_map.c, branch v6.19.11

bpf: Remove attach_type in sockmap_link

2025-07-11T17:51:55+00:00

Use attach_type in bpf_link, and remove it in sockmap_link. Signed-off-by: Tao Chen Signed-off-by: Andrii Nakryiko Acked-by: Daniel Borkmann Acked-by: Jiri Olsa Link: https://lore.kernel.org/bpf/20250710032038.888700-4-chen.dylane@linux.dev

bpf: Add attach_type field to bpf_link

2025-07-11T17:51:55+00:00

Attach_type will be set when a link is created by user. It is better to record attach_type in bpf_link generically and have it available universally for all link types. So add the attach_type field in bpf_link and move the sleepable field to avoid unnecessary gap padding. Signed-off-by: Tao Chen Signed-off-by: Andrii Nakryiko Acked-by: Daniel Borkmann Acked-by: Jiri Olsa Link: https://lore.kernel.org/bpf/20250710032038.888700-2-chen.dylane@linux.dev

Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

2025-02-20T23:37:17+00:00

Pull BPF fixes from Daniel Borkmann: - Fix a soft-lockup in BPF arena_map_free on 64k page size kernels (Alan Maguire) - Fix a missing allocation failure check in BPF verifier's acquire_lock_state (Kumar Kartikeya Dwivedi) - Fix a NULL-pointer dereference in trace_kfree_skb by adding kfree_skb to the raw_tp_null_args set (Kuniyuki Iwashima) - Fix a deadlock when freeing BPF cgroup storage (Abel Wu) - Fix a syzbot-reported deadlock when holding BPF map's freeze_mutex (Andrii Nakryiko) - Fix a use-after-free issue in bpf_test_init when eth_skb_pkt_type is accessing skb data not containing an Ethernet header (Shigeru Yoshida) - Fix skipping non-existing keys in generic_map_lookup_batch (Yan Zhai) - Several BPF sockmap fixes to address incorrect TCP copied_seq calculations, which prevented correct data reads from recv(2) in user space (Jiayuan Chen) - Two fixes for BPF map lookup nullness elision (Daniel Xu) - Fix a NULL-pointer dereference from vmlinux BTF lookup in bpf_sk_storage_tracing_allowed (Jared Kangas) * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: selftests: bpf: test batch lookup on array of maps with holes bpf: skip non exist keys in generic_map_lookup_batch bpf: Handle allocation failure in acquire_lock_state bpf: verifier: Disambiguate get_constant_map_key() errors bpf: selftests: Test constant key extraction on irrelevant maps bpf: verifier: Do not extract constant map keys for irrelevant maps bpf: Fix softlockup in arena_map_free on 64k page kernel net: Add rx_skb of kfree_skb to raw_tp_null_args[]. bpf: Fix deadlock when freeing cgroup storage selftests/bpf: Add strparser test for bpf selftests/bpf: Fix invalid flag of recv() bpf: Disable non stream socket for strparser bpf: Fix wrong copied_seq calculation strparser: Add read_sock callback bpf: avoid holding freeze_mutex during mmap operation bpf: unify VM_WRITE vs VM_MAYWRITE use in BPF map mmaping logic selftests/bpf: Adjust data size to have ETH_HLEN bpf, test_run: Fix use-after-free issue in eth_skb_pkt_type() bpf: Remove unnecessary BTF lookups in bpf_sk_storage_tracing_allowed

sockmap, vsock: For connectible sockets allow only connected

2025-02-18T11:00:00+00:00

sockmap expects all vsocks to have a transport assigned, which is expressed in vsock_proto::psock_update_sk_prot(). However, there is an edge case where an unconnected (connectible) socket may lose its previously assigned transport. This is handled with a NULL check in the vsock/BPF recv path. Another design detail is that listening vsocks are not supposed to have any transport assigned at all. Which implies they are not supported by the sockmap. But this is complicated by the fact that a socket, before switching to TCP_LISTEN, may have had some transport assigned during a failed connect() attempt. Hence, we may end up with a listening vsock in a sockmap, which blows up quickly: KASAN: null-ptr-deref in range [0x0000000000000120-0x0000000000000127] CPU: 7 UID: 0 PID: 56 Comm: kworker/7:0 Not tainted 6.14.0-rc1+ Workqueue: vsock-loopback vsock_loopback_work RIP: 0010:vsock_read_skb+0x4b/0x90 Call Trace: sk_psock_verdict_data_ready+0xa4/0x2e0 virtio_transport_recv_pkt+0x1ca8/0x2acc vsock_loopback_work+0x27d/0x3f0 process_one_work+0x846/0x1420 worker_thread+0x5b3/0xf80 kthread+0x35a/0x700 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x1a/0x30 For connectible sockets, instead of relying solely on the state of vsk->transport, tell sockmap to only allow those representing established connections. This aligns with the behaviour for AF_INET and AF_UNIX. Fixes: 634f1a7110b4 ("vsock: support sockmap") Signed-off-by: Michal Luczaj Acked-by: Stefano Garzarella Signed-off-by: Paolo Abeni

bpf: Disable non stream socket for strparser

2025-01-29T21:32:32+00:00

Currently, only TCP supports strparser, but sockmap doesn't intercept non-TCP connections to attach strparser. For example, with UDP, although the read/write handlers are replaced, strparser is not executed due to the lack of a read_sock operation. Furthermore, in udp_bpf_recvmsg(), it checks whether the psock has data, and if not, it falls back to the native UDP read interface, making UDP + strparser appear to read correctly. According to its commit history, this behavior is unexpected. Moreover, since UDP lacks the concept of streams, we intercept it directly. Fixes: 1fa1fe8ff161 ("bpf, sockmap: Test shutdown() correctly exits epoll and recv()=0") Signed-off-by: Jiayuan Chen Signed-off-by: Martin KaFai Lau Acked-by: Jakub Sitnicki Acked-by: John Fastabend Link: https://patch.msgid.link/20250122100917.49845-4-mrpre@163.com

bpf, sockmap: Fix race between element replace and close()

2024-12-10T16:38:05+00:00

Element replace (with a socket different from the one stored) may race with socket's close() link popping & unlinking. __sock_map_delete() unconditionally unrefs the (wrong) element: // set map[0] = s0 map_update_elem(map, 0, s0) // drop fd of s0 close(s0) sock_map_close() lock_sock(sk) (s0!) sock_map_remove_links(sk) link = sk_psock_link_pop() sock_map_unlink(sk, link) sock_map_delete_from_link // replace map[0] with s1 map_update_elem(map, 0, s1) sock_map_update_elem (s1!) lock_sock(sk) sock_map_update_common psock = sk_psock(sk) spin_lock(&stab->lock) osk = stab->sks[idx] sock_map_add_link(..., &stab->sks[idx]) sock_map_unref(osk, &stab->sks[idx]) psock = sk_psock(osk) sk_psock_put(sk, psock) if (refcount_dec_and_test(&psock)) sk_psock_drop(sk, psock) spin_unlock(&stab->lock) unlock_sock(sk) __sock_map_delete spin_lock(&stab->lock) sk = *psk // s1 replaced s0; sk == s1 if (!sk_test || sk_test == sk) // sk_test (s0) != sk (s1); no branch sk = xchg(psk, NULL) if (sk) sock_map_unref(sk, psk) // unref s1; sks[idx] will dangle psock = sk_psock(sk) sk_psock_put(sk, psock) if (refcount_dec_and_test()) sk_psock_drop(sk, psock) spin_unlock(&stab->lock) release_sock(sk) Then close(map) enqueues bpf_map_free_deferred, which finally calls sock_map_free(). This results in some refcount_t warnings along with a KASAN splat [1]. Fix __sock_map_delete(), do not allow sock_map_unref() on elements that may have been replaced. [1]: BUG: KASAN: slab-use-after-free in sock_map_free+0x10e/0x330 Write of size 4 at addr ffff88811f5b9100 by task kworker/u64:12/1063 CPU: 14 UID: 0 PID: 1063 Comm: kworker/u64:12 Not tainted 6.12.0+ #125 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 Workqueue: events_unbound bpf_map_free_deferred Call Trace: dump_stack_lvl+0x68/0x90 print_report+0x174/0x4f6 kasan_report+0xb9/0x190 kasan_check_range+0x10f/0x1e0 sock_map_free+0x10e/0x330 bpf_map_free_deferred+0x173/0x320 process_one_work+0x846/0x1420 worker_thread+0x5b3/0xf80 kthread+0x29e/0x360 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x1a/0x30 Allocated by task 1202: kasan_save_stack+0x1e/0x40 kasan_save_track+0x10/0x30 __kasan_slab_alloc+0x85/0x90 kmem_cache_alloc_noprof+0x131/0x450 sk_prot_alloc+0x5b/0x220 sk_alloc+0x2c/0x870 unix_create1+0x88/0x8a0 unix_create+0xc5/0x180 __sock_create+0x241/0x650 __sys_socketpair+0x1ce/0x420 __x64_sys_socketpair+0x92/0x100 do_syscall_64+0x93/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e Freed by task 46: kasan_save_stack+0x1e/0x40 kasan_save_track+0x10/0x30 kasan_save_free_info+0x37/0x60 __kasan_slab_free+0x4b/0x70 kmem_cache_free+0x1a1/0x590 __sk_destruct+0x388/0x5a0 sk_psock_destroy+0x73e/0xa50 process_one_work+0x846/0x1420 worker_thread+0x5b3/0xf80 kthread+0x29e/0x360 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x1a/0x30 The buggy address belongs to the object at ffff88811f5b9080 which belongs to the cache UNIX-STREAM of size 1984 The buggy address is located 128 bytes inside of freed 1984-byte region [ffff88811f5b9080, ffff88811f5b9840) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11f5b8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888127d49401 flags: 0x17ffffc0000040(head|node=0|zone=2|lastcpupid=0x1fffff) page_type: f5(slab) raw: 0017ffffc0000040 ffff8881042e4500 dead000000000122 0000000000000000 raw: 0000000000000000 00000000800f000f 00000001f5000000 ffff888127d49401 head: 0017ffffc0000040 ffff8881042e4500 dead000000000122 0000000000000000 head: 0000000000000000 00000000800f000f 00000001f5000000 ffff888127d49401 head: 0017ffffc0000003 ffffea00047d6e01 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88811f5b9000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88811f5b9080: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811f5b9180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811f5b9200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Disabling lock debugging due to kernel taint refcount_t: addition on 0; use-after-free. WARNING: CPU: 14 PID: 1063 at lib/refcount.c:25 refcount_warn_saturate+0xce/0x150 CPU: 14 UID: 0 PID: 1063 Comm: kworker/u64:12 Tainted: G B 6.12.0+ #125 Tainted: [B]=BAD_PAGE Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 Workqueue: events_unbound bpf_map_free_deferred RIP: 0010:refcount_warn_saturate+0xce/0x150 Code: 34 73 eb 03 01 e8 82 53 ad fe 0f 0b eb b1 80 3d 27 73 eb 03 00 75 a8 48 c7 c7 80 bd 95 84 c6 05 17 73 eb 03 01 e8 62 53 ad fe <0f> 0b eb 91 80 3d 06 73 eb 03 00 75 88 48 c7 c7 e0 bd 95 84 c6 05 RSP: 0018:ffff88815c49fc70 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff88811f5b9100 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001 RBP: 0000000000000002 R08: 0000000000000001 R09: ffffed10bcde6349 R10: ffff8885e6f31a4b R11: 0000000000000000 R12: ffff88813be0b000 R13: ffff88811f5b9100 R14: ffff88811f5b9080 R15: ffff88813be0b024 FS: 0000000000000000(0000) GS:ffff8885e6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055dda99b0250 CR3: 000000015dbac000 CR4: 0000000000752ef0 PKRU: 55555554 Call Trace: ? __warn.cold+0x5f/0x1ff ? refcount_warn_saturate+0xce/0x150 ? report_bug+0x1ec/0x390 ? handle_bug+0x58/0x90 ? exc_invalid_op+0x13/0x40 ? asm_exc_invalid_op+0x16/0x20 ? refcount_warn_saturate+0xce/0x150 sock_map_free+0x2e5/0x330 bpf_map_free_deferred+0x173/0x320 process_one_work+0x846/0x1420 worker_thread+0x5b3/0xf80 kthread+0x29e/0x360 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x1a/0x30 irq event stamp: 10741 hardirqs last enabled at (10741): [] asm_sysvec_apic_timer_interrupt+0x16/0x20 hardirqs last disabled at (10740): [] handle_softirqs+0x60d/0x770 softirqs last enabled at (10506): [] __irq_exit_rcu+0x109/0x210 softirqs last disabled at (10301): [] __irq_exit_rcu+0x109/0x210 refcount_t: underflow; use-after-free. WARNING: CPU: 14 PID: 1063 at lib/refcount.c:28 refcount_warn_saturate+0xee/0x150 CPU: 14 UID: 0 PID: 1063 Comm: kworker/u64:12 Tainted: G B W 6.12.0+ #125 Tainted: [B]=BAD_PAGE, [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 Workqueue: events_unbound bpf_map_free_deferred RIP: 0010:refcount_warn_saturate+0xee/0x150 Code: 17 73 eb 03 01 e8 62 53 ad fe 0f 0b eb 91 80 3d 06 73 eb 03 00 75 88 48 c7 c7 e0 bd 95 84 c6 05 f6 72 eb 03 01 e8 42 53 ad fe <0f> 0b e9 6e ff ff ff 80 3d e6 72 eb 03 00 0f 85 61 ff ff ff 48 c7 RSP: 0018:ffff88815c49fc70 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff88811f5b9100 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001 RBP: 0000000000000003 R08: 0000000000000001 R09: ffffed10bcde6349 R10: ffff8885e6f31a4b R11: 0000000000000000 R12: ffff88813be0b000 R13: ffff88811f5b9100 R14: ffff88811f5b9080 R15: ffff88813be0b024 FS: 0000000000000000(0000) GS:ffff8885e6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055dda99b0250 CR3: 000000015dbac000 CR4: 0000000000752ef0 PKRU: 55555554 Call Trace: ? __warn.cold+0x5f/0x1ff ? refcount_warn_saturate+0xee/0x150 ? report_bug+0x1ec/0x390 ? handle_bug+0x58/0x90 ? exc_invalid_op+0x13/0x40 ? asm_exc_invalid_op+0x16/0x20 ? refcount_warn_saturate+0xee/0x150 sock_map_free+0x2d3/0x330 bpf_map_free_deferred+0x173/0x320 process_one_work+0x846/0x1420 worker_thread+0x5b3/0xf80 kthread+0x29e/0x360 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x1a/0x30 irq event stamp: 10741 hardirqs last enabled at (10741): [] asm_sysvec_apic_timer_interrupt+0x16/0x20 hardirqs last disabled at (10740): [] handle_softirqs+0x60d/0x770 softirqs last enabled at (10506): [] __irq_exit_rcu+0x109/0x210 softirqs last disabled at (10301): [] __irq_exit_rcu+0x109/0x210 Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: Michal Luczaj Signed-off-by: Daniel Borkmann Reviewed-by: John Fastabend Link: https://lore.kernel.org/bpf/20241202-sockmap-replace-v1-3-1e88579e7bd5@rbox.co

bpf, sockmap: Fix update element with same

2024-12-10T16:37:02+00:00

Consider a sockmap entry being updated with the same socket: osk = stab->sks[idx]; sock_map_add_link(psock, link, map, &stab->sks[idx]); stab->sks[idx] = sk; if (osk) sock_map_unref(osk, &stab->sks[idx]); Due to sock_map_unref(), which invokes sock_map_del_link(), all the psock's links for stab->sks[idx] are torn: list_for_each_entry_safe(link, tmp, &psock->link, list) { if (link->link_raw == link_raw) { ... list_del(&link->list); sk_psock_free_link(link); } } And that includes the new link sock_map_add_link() added just before the unref. This results in a sockmap holding a socket, but without the respective link. This in turn means that close(sock) won't trigger the cleanup, i.e. a closed socket will not be automatically removed from the sockmap. Stop tearing the links when a matching link_raw is found. Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: Michal Luczaj Signed-off-by: Daniel Borkmann Reviewed-by: John Fastabend Link: https://lore.kernel.org/bpf/20241202-sockmap-replace-v1-1-1e88579e7bd5@rbox.co

sock_map: fix a NULL pointer dereference in sock_map_link_update_prog()

2024-10-29T01:44:14+00:00

The following race condition could trigger a NULL pointer dereference: sock_map_link_detach(): sock_map_link_update_prog(): mutex_lock(&sockmap_mutex); ... sockmap_link->map = NULL; mutex_unlock(&sockmap_mutex); mutex_lock(&sockmap_mutex); ... sock_map_prog_link_lookup(sockmap_link->map); mutex_unlock(&sockmap_mutex); Fix it by adding a NULL pointer check. In this specific case, it makes no sense to update a link which is being released. Reported-by: Ruan Bonan Fixes: 699c23f02c65 ("bpf: Add bpf_link support for sk_msg and sk_skb progs") Cc: Yonghong Song Cc: John Fastabend Cc: Jakub Sitnicki Signed-off-by: Cong Wang Link: https://lore.kernel.org/r/20241026185522.338562-1-xiyou.wangcong@gmail.com Signed-off-by: Martin KaFai Lau

bpf, sockmap: SK_DROP on attempted redirects of unsupported af_vsock

2024-10-17T11:02:54+00:00

Don't mislead the callers of bpf_{sk,msg}_redirect_{map,hash}(): make sure to immediately and visibly fail the forwarding of unsupported af_vsock packets. Fixes: 634f1a7110b4 ("vsock: support sockmap") Signed-off-by: Michal Luczaj Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20241013-vsock-fixes-for-redir-v2-1-d6577bbfe742@rbox.co

Merge tag 'bpf-next-6.12-struct-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2024-09-24T21:54:26+00:00

Pull bpf 'struct fd' updates from Alexei Starovoitov: "This includes struct_fd BPF changes from Al and Andrii" * tag 'bpf-next-6.12-struct-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: bpf: convert bpf_token_create() to CLASS(fd, ...) security,bpf: constify struct path in bpf_token_create() LSM hook bpf: more trivial fdget() conversions bpf: trivial conversions for fdget() bpf: switch maps to CLASS(fd, ...) bpf: factor out fetching bpf_map from FD and adding it to used_maps list bpf: switch fdget_raw() uses to CLASS(fd_raw, ...) bpf: convert __bpf_prog_get() to CLASS(fd, ...)