kernel/git/stable/linux.git/net/sctp/auth.c, branch linux-7.2.y

sctp: validate cookie AUTH state before use

2026-08-07T22:02:32+00:00

When cookie authentication is disabled, COOKIE_ECHO restores fixed-size AUTH fields directly from peer-controlled cookie bytes. A forged RANDOM length, HMAC list, or CHUNKS list can then reach association consumers with lengths or identifiers that were never validated against the local backing arrays. A forged RANDOM length can cause out-of-bounds reads during key-vector construction. A forged HMAC identifier also caused a 32-byte write past a zero-length AUTH chunk, providing a primitive for a local privilege escalation chain. Validate the cookie's RANDOM, HMACS, and CHUNKS parameters at the cookie trust boundary before copying them into the association. Reject invalid types, malformed lengths, unsupported HMAC identifiers, HMAC lists without SHA1, and forbidden chunk ids. Fixes: bbd0d59809f9 ("[SCTP]: Implement the receive and verification of AUTH chunk") Fixes: 1f485649f529 ("[SCTP]: Implement SCTP-AUTH internals") Signed-off-by: Jérémy Jean Acked-by: Xin Long Link: https://patch.msgid.link/20260804200042.2412009-1-Jeremy.Jean@oss.cyber.gouv.fr Signed-off-by: Jakub Kicinski

sctp: fix auth_chunk_list capacity check in sctp_auth_ep_add_chunkid

2026-07-21T19:30:38+00:00

sctp_auth_ep_add_chunkid() uses SCTP_NUM_CHUNK_TYPES (20) as the capacity limit for ep->auth_chunk_list, allowing it to hold up to 20 chunk entries (param_hdr.length up to 24). However, the copy destination asoc->c.auth_chunks in struct sctp_cookie is only SCTP_AUTH_MAX_CHUNKS (16) entries (20 bytes). When more than 16 chunks are added, sctp_association_init() memcpy overflows the destination by up to 4 bytes. Fix by using SCTP_AUTH_MAX_CHUNKS as the capacity limit, matching the destination capacity. Fixes: 1f485649f529 ("[SCTP]: Implement SCTP-AUTH internals") Signed-off-by: HanQuan Acked-by: Xin Long Link: https://patch.msgid.link/20260713032021.3491702-1-zhoujian.zja@antgroup.com Signed-off-by: Jakub Kicinski

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

sctp: Use HMAC-SHA1 and HMAC-SHA256 library for chunk authentication

2025-08-20T02:36:25+00:00

For SCTP chunk authentication, use the HMAC-SHA1 and HMAC-SHA256 library functions instead of crypto_shash. This is simpler and faster. There's no longer any need to pre-allocate 'crypto_shash' objects; the SCTP code now simply calls into the HMAC code directly. As part of this, make SCTP always support both HMAC-SHA1 and HMAC-SHA256. Previously, it only guaranteed support for HMAC-SHA1. However, HMAC-SHA256 tended to be supported too anyway, as it was supported if CONFIG_CRYPTO_SHA256 was enabled elsewhere in the kconfig. Acked-by: Xin Long Signed-off-by: Eric Biggers Link: https://patch.msgid.link/20250818205426.30222-4-ebiggers@kernel.org Signed-off-by: Jakub Kicinski

sctp: delete the nested flexible array hmac

2023-04-21T07:19:30+00:00

This patch deletes the flexible-array hmac[] from the structure sctp_authhdr to avoid some sparse warnings: # make C=2 CF="-Wflexible-array-nested" M=./net/sctp/ net/sctp/auth.c: note: in included file (through include/net/sctp/structs.h, include/net/sctp/sctp.h): ./include/linux/sctp.h:735:29: warning: nested flexible array Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: handle the error returned from sctp_auth_asoc_init_active_key

2022-09-30T11:36:40+00:00

When it returns an error from sctp_auth_asoc_init_active_key(), the active_key is actually not updated. The old sh_key will be freeed while it's still used as active key in asoc. Then an use-after-free will be triggered when sending patckets, as found by syzbot: sctp_auth_shkey_hold+0x22/0xa0 net/sctp/auth.c:112 sctp_set_owner_w net/sctp/socket.c:132 [inline] sctp_sendmsg_to_asoc+0xbd5/0x1a20 net/sctp/socket.c:1863 sctp_sendmsg+0x1053/0x1d50 net/sctp/socket.c:2025 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 This patch is to fix it by not replacing the sh_key when it returns errors from sctp_auth_asoc_init_active_key() in sctp_auth_set_key(). For sctp_auth_set_active_key(), old active_key_id will be set back to asoc->active_key_id when the same thing happens. Fixes: 58acd1009226 ("sctp: update active_key for asoc when old key is being replaced") Reported-by: syzbot+a236dd8e9622ed8954a3@syzkaller.appspotmail.com Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: move the active_key update after sh_keys is added

2021-08-03T10:43:43+00:00

In commit 58acd1009226 ("sctp: update active_key for asoc when old key is being replaced"), sctp_auth_asoc_init_active_key() is called to update the active_key right after the old key is deleted and before the new key is added, and it caused that the active_key could be found with the key_id. In Ying Xu's testing, the BUG_ON in sctp_auth_asoc_init_active_key() was triggered: [ ] kernel BUG at net/sctp/auth.c:416! [ ] RIP: 0010:sctp_auth_asoc_init_active_key.part.8+0xe7/0xf0 [sctp] [ ] Call Trace: [ ] sctp_auth_set_key+0x16d/0x1b0 [sctp] [ ] sctp_setsockopt.part.33+0x1ba9/0x2bd0 [sctp] [ ] __sys_setsockopt+0xd6/0x1d0 [ ] __x64_sys_setsockopt+0x20/0x30 [ ] do_syscall_64+0x5b/0x1a0 So fix it by moving the active_key update after sh_keys is added. Fixes: 58acd1009226 ("sctp: update active_key for asoc when old key is being replaced") Reported-by: Ying Xu Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: update active_key for asoc when old key is being replaced

2021-07-21T15:44:44+00:00

syzbot reported a call trace: BUG: KASAN: use-after-free in sctp_auth_shkey_hold+0x22/0xa0 net/sctp/auth.c:112 Call Trace: sctp_auth_shkey_hold+0x22/0xa0 net/sctp/auth.c:112 sctp_set_owner_w net/sctp/socket.c:131 [inline] sctp_sendmsg_to_asoc+0x152e/0x2180 net/sctp/socket.c:1865 sctp_sendmsg+0x103b/0x1d30 net/sctp/socket.c:2027 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:821 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:723 This is an use-after-free issue caused by not updating asoc->shkey after it was replaced in the key list asoc->endpoint_shared_keys, and the old key was freed. This patch is to fix by also updating active_key for asoc when old key is being replaced with a new one. Note that this issue doesn't exist in sctp_auth_del_key_id(), as it's not allowed to delete the active_key from the asoc. Fixes: 1b1e0bc99474 ("sctp: add refcnt support for sh_key") Reported-by: syzbot+b774577370208727d12b@syzkaller.appspotmail.com Signed-off-by: Xin Long Signed-off-by: David S. Miller

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

2020-10-08T22:44:50+00:00

Small conflict around locking in rxrpc_process_event() - channel_lock moved to bundle in next, while state lock needs _bh() from net. Signed-off-by: Jakub Kicinski

sctp: fix sctp_auth_init_hmacs() error path

2020-10-08T19:19:51+00:00

After freeing ep->auth_hmacs we have to clear the pointer or risk use-after-free as reported by syzbot: BUG: KASAN: use-after-free in sctp_auth_destroy_hmacs net/sctp/auth.c:509 [inline] BUG: KASAN: use-after-free in sctp_auth_destroy_hmacs net/sctp/auth.c:501 [inline] BUG: KASAN: use-after-free in sctp_auth_free+0x17e/0x1d0 net/sctp/auth.c:1070 Read of size 8 at addr ffff8880a8ff52c0 by task syz-executor941/6874 CPU: 0 PID: 6874 Comm: syz-executor941 Not tainted 5.9.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x198/0x1fd lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 sctp_auth_destroy_hmacs net/sctp/auth.c:509 [inline] sctp_auth_destroy_hmacs net/sctp/auth.c:501 [inline] sctp_auth_free+0x17e/0x1d0 net/sctp/auth.c:1070 sctp_endpoint_destroy+0x95/0x240 net/sctp/endpointola.c:203 sctp_endpoint_put net/sctp/endpointola.c:236 [inline] sctp_endpoint_free+0xd6/0x110 net/sctp/endpointola.c:183 sctp_destroy_sock+0x9c/0x3c0 net/sctp/socket.c:4981 sctp_v6_destroy_sock+0x11/0x20 net/sctp/socket.c:9415 sk_common_release+0x64/0x390 net/core/sock.c:3254 sctp_close+0x4ce/0x8b0 net/sctp/socket.c:1533 inet_release+0x12e/0x280 net/ipv4/af_inet.c:431 inet6_release+0x4c/0x70 net/ipv6/af_inet6.c:475 __sock_release+0xcd/0x280 net/socket.c:596 sock_close+0x18/0x20 net/socket.c:1277 __fput+0x285/0x920 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:141 exit_task_work include/linux/task_work.h:25 [inline] do_exit+0xb7d/0x29f0 kernel/exit.c:806 do_group_exit+0x125/0x310 kernel/exit.c:903 __do_sys_exit_group kernel/exit.c:914 [inline] __se_sys_exit_group kernel/exit.c:912 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:912 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x43f278 Code: Bad RIP value. RSP: 002b:00007fffe0995c38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043f278 RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00000000004bf068 R08: 00000000000000e7 R09: ffffffffffffffd0 R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 6874: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 kmem_cache_alloc_trace+0x174/0x300 mm/slab.c:3554 kmalloc include/linux/slab.h:554 [inline] kmalloc_array include/linux/slab.h:593 [inline] kcalloc include/linux/slab.h:605 [inline] sctp_auth_init_hmacs+0xdb/0x3b0 net/sctp/auth.c:464 sctp_auth_init+0x8a/0x4a0 net/sctp/auth.c:1049 sctp_setsockopt_auth_supported net/sctp/socket.c:4354 [inline] sctp_setsockopt+0x477e/0x97f0 net/sctp/socket.c:4631 __sys_setsockopt+0x2db/0x610 net/socket.c:2132 __do_sys_setsockopt net/socket.c:2143 [inline] __se_sys_setsockopt net/socket.c:2140 [inline] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2140 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 6874: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422 __cache_free mm/slab.c:3422 [inline] kfree+0x10e/0x2b0 mm/slab.c:3760 sctp_auth_destroy_hmacs net/sctp/auth.c:511 [inline] sctp_auth_destroy_hmacs net/sctp/auth.c:501 [inline] sctp_auth_init_hmacs net/sctp/auth.c:496 [inline] sctp_auth_init_hmacs+0x2b7/0x3b0 net/sctp/auth.c:454 sctp_auth_init+0x8a/0x4a0 net/sctp/auth.c:1049 sctp_setsockopt_auth_supported net/sctp/socket.c:4354 [inline] sctp_setsockopt+0x477e/0x97f0 net/sctp/socket.c:4631 __sys_setsockopt+0x2db/0x610 net/socket.c:2132 __do_sys_setsockopt net/socket.c:2143 [inline] __se_sys_setsockopt net/socket.c:2140 [inline] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2140 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 1f485649f529 ("[SCTP]: Implement SCTP-AUTH internals") Signed-off-by: Eric Dumazet Cc: Vlad Yasevich Cc: Neil Horman Cc: Marcelo Ricardo Leitner Acked-by: Marcelo Ricardo Leitner Signed-off-by: Jakub Kicinski