kernel/linux.git/net/tls, branch v7.2.3

tls: device: fix out-of-bounds write in tls_append_frag()

2026-09-02T12:33:18+00:00

commit b17cf742eaad70ae29ac558cefb3aa9bbeea03d4 upstream. Found with syzkaller and a local syzbot instance running on top of a netdevsim TLS offload emulation; tls_device.c is otherwise only reachable on a machine with a NIC that implements the offload. tls_push_data() only checks whether the open record still has room for another frag at the bottom of its loop, and the MSG_MORE early break skips that check. The record survives to the next syscall with the frag count it already had, and tls_append_frag() does not check either, so with TLS_TX_ZEROCOPY_RO every splice(SPLICE_F_MORE) of a byte or two adds a non-coalescing pipe page and num_frags walks off the end of tls_record_info.frags[MAX_SKB_FRAGS]. Once the record is pushed, tls_push_record() runs the same index over sg_tx_data[MAX_SKB_FRAGS] and the sg_set_page() writes land on the destruct_work that follows it, which the workqueue then calls. The byte limit is fine because copy drops to 0 and the loop falls through to the same check; the frag count has no such feedback. Push the record rather than keep a full one open, which is what a plain TCP socket does - tcp_sendmsg_locked() uses tcp_mark_push() and new_segment in both the copy and the MSG_SPLICE_PAGES paths, and tls_sw already sets full_record when the sk_msg ring fills up, MSG_MORE or not. BUG: KASAN: slab-out-of-bounds in tls_append_frag ( net/tls/tls_device.c:269) Write of size 8 at addr ffff8881104d1530 by task tls_oob/450 CPU: 2 UID: 0 PID: 450 Comm: tls_oob Not tainted 7.2.0-rc7+ #329 PREEMPT Call Trace: dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120) print_report (mm/kasan/report.c:378 mm/kasan/report.c:482) kasan_report (mm/kasan/report.c:595) tls_append_frag (net/tls/tls_device.c:269) tls_push_data (net/tls/tls_device.c:518) tls_device_sendmsg (net/tls/tls_device.c:583) inet_sendmsg (net/ipv4/af_inet.c:865) sock_sendmsg (net/socket.c:775 net/socket.c:790 net/socket.c:813) splice_to_socket (fs/splice.c:884) do_splice (fs/splice.c:936 fs/splice.c:1349) __do_splice (fs/splice.c:1431) __x64_sys_splice (fs/splice.c:1634 fs/splice.c:1616) do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) and, once the record is pushed: UBSAN: array-index-out-of-bounds in net/tls/tls_device.c:300:24 index 18 is out of range for type 'skb_frag_t [17]' UBSAN: array-index-out-of-bounds in net/tls/tls_device.c:301:41 index 18 is out of range for type 'scatterlist [17]' UBSAN: array-index-out-of-bounds in net/tls/tls_device.c:302:39 index 18 is out of range for type 'scatterlist [17]' UBSAN: array-index-out-of-bounds in net/tls/tls_device.c:307:38 index 26 is out of range for type 'scatterlist [17]' kernel tried to execute NX-protected page - exploit attempt? (uid: 0) BUG: unable to handle page fault for address: ffffea000411a680 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0011) - permissions violation Oops: Oops: 0011 [#1] SMP KASAN PTI Workqueue: ktls_device_destruct 0xffffea000411a680 RIP: 0010:0xffffea000411a680 Call Trace: worker_thread (kernel/workqueue.c:3405 kernel/workqueue.c:3486) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:158) ret_from_fork_asm (arch/x86/entry/entry_64.S:245) Fixes: e8f69799810c ("net/tls: Add generic NIC offload infrastructure") Cc: stable@vger.kernel.org Signed-off-by: Jiayuan Chen Link: https://patch.msgid.link/20260823084758.20936-1-jiayuan.chen@linux.dev Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

net/tls: Fail tls_sw_splice_read() after a failed async decrypt

2026-08-11T13:39:00+00:00

When an async decrypt fails, tls_decrypt_done() records the error in ctx->async_wait.err and calls tls_err_abort(), which stores it in sk_err. tls_sw_recvmsg() and tls_sw_read_sock() each read async_wait.err once they hold the reader lock and fail the call: a record that did not authenticate breaks the connection. tls_sw_splice_read() has no such check, and sk_err does not stand in for one. tls_rx_rec_wait() tests sk_err only inside the loop it skips whenever a record is already parsed, and the first reader to reach sock_error() clears it, while async_wait.err persists. A splice therefore keeps delivering records on a connection that recvmsg() and read_sock() refuse to read. Read async_wait.err in tls_sw_splice_read() as the other two readers do. Fixes: f314bfee81b1 ("tls: rx: return the already-copied data on crypto error") Reviewed-by: Jakub Kicinski Signed-off-by: Chuck Lever Reviewed-by: Sabrina Dubroca Link: https://patch.msgid.link/20260806-tls-splice-crypto-fix-v1-1-a2624005a286@kernel.org Signed-off-by: Paolo Abeni

tls: don't abort the connection on signal-interrupted sends

2026-08-06T16:38:20+00:00

When a signal interrupts a blocking send, tls_tx_records() treats the resulting -ERESTARTSYS as a transmission failure and marks the socket errored via tls_err_abort() with the raw error code. Later syscalls return the kernel-internal errno 512 (ERESTARTSYS) to userspace, as the signal it stems from is no longer pending during syscall exit and thus never translated. An interrupted send is not a connection error: the partially sent record stays queued and is resent later. Interrupt error codes are therefore excluded from the abort in the same way as -EAGAIN. Fixes: b341ca51d267 ("tls: Fix tls_sw_sendmsg error handling") Signed-off-by: Maximilian Immanuel Brandtner Link: https://patch.msgid.link/20260805063109.1772314-1-maxbr@linux.ibm.com Signed-off-by: Jakub Kicinski

tls: rx: restore msg_iter before TLS 1.3 optimistic retry

2026-08-06T16:08:58+00:00

tls_decrypt_sg() advances msg->msg_iter when it maps user pages for the optimistic TLS 1.3 zero-copy path. If the decrypted record turns out not to be unpadded application data, tls_decrypt_sw() retries into a kernel skb, but leaves the iterator advanced. The subsequent copy from the skb then writes decrypted bytes again at a later point in the caller iovecs while recvmsg() reports only the post-retry length. A TLS peer can trigger this after the receiver enables TLS_RX_EXPECT_NO_PAD. Revert the iterator by the number of bytes consumed by the optimistic mapping before retrying without zero-copy. Add a selftest which sends a TLS 1.3 control record with TLS_RX_EXPECT_NO_PAD enabled and verifies that recvmsg() does not overwrite later iovecs beyond the returned length. Fixes: ce61327ce989 ("tls: rx: support optimistic decrypt to user buffer with TLS 1.3") Cc: stable@vger.kernel.org Signed-off-by: Jérémy Jean Link: https://patch.msgid.link/20260804125528.2139928-1-Jeremy.Jean@oss.cyber.gouv.fr Signed-off-by: Jakub Kicinski

tls: don't leave a full plaintext sk_msg ring unpushed

2026-08-06T16:01:54+00:00

When the copy path in tls_sw_sendmsg_locked() adds the fragment that fills the plaintext sk_msg ring, it does not set full_record, so the record is left full and unpushed. A later splice() then adds to an already full ring: sk_msg_page_add() has no fullness check of its own, so sg.end wraps onto sg.start and the ring appears empty. Fragments added after that overwrite live entries, and sg.size no longer matches what is reachable between sg.start and sg.end, so pushing the record runs the scatterwalk off the end of the scatterlist. An unprivileged user can trigger this on a loopback TCP socket with the "tls" ULP attached: BUG: kernel NULL pointer dereference, address: 0000000000000008 RIP: 0010:memcpy_from_scatterwalk+0x32/0xc0 Call Trace: skcipher_walk_next+0x1d1/0x2c0 gcm_encrypt_aesni_avx+0x1e9/0x220 bpf_exec_tx_verdict+0x3bb/0x860 tls_sw_sendmsg+0xa1a/0xca0 __sys_sendto+0x1da/0x1f0 Set full_record in the copy path when the ring becomes full, and push a record that is already full on entry to the sendmsg loop. Suggested-by: Sabrina Dubroca Fixes: fe1e81d4f73b ("tls/sw: Support MSG_SPLICE_PAGES") Cc: stable@vger.kernel.org Signed-off-by: chanyoung Link: https://patch.msgid.link/20260804052837.49015-2-ppoo1220@gmail.com Signed-off-by: Jakub Kicinski

tls: device: push pending open record on splice EOF

2026-07-21T21:50:50+00:00

On kTLS device-offload sockets, sendfile() with count > EOF can reach ->splice_eof() with a fully assembled but still-open TLS record left pending. tls_device_splice_eof() only flushes partially sent records, so an abrupt close() can drop the final record and the peer receives a short file. Fix tls_device_splice_eof() to also push pending open records. This matches the software path, where splice EOF already flushes pending open records. Fixes: d4c1e80b0d1b ("tls/device: Use splice_eof() to flush") Link: https://lore.kernel.org/netdev/CAMPsyauZ+jzG9AysO0FWv6ZY0kvCUpjX_U7o=oOjCuOQ87BCgg@mail.gmail.com/ Reported-by: Nils Juenemann Signed-off-by: Rishikesh Jethwani Tested-by: Nils Juenemann Link: https://patch.msgid.link/20260709224436.1608993-2-rjethwani@purestorage.com Signed-off-by: Jakub Kicinski

net/tls: Consume empty data records in tls_sw_read_sock()

2026-07-07T08:12:11+00:00

A peer may send a zero-length TLS application_data record; TLS 1.3 explicitly permits these as a traffic-analysis countermeasure (RFC 8446, Section 5.1). After decryption such a record has full_len == 0. tls_sw_read_sock() hands it to the read_actor, which has no payload to consume and returns zero. The loop treats a zero return as backpressure (used <= 0), requeues the skb at the head of rx_list, and stops. rx_list is serviced head-first on the next call, so the empty record is dequeued, fails the same way, and is requeued again; every later record on the connection is blocked behind it. tls_sw_recvmsg() does not stall on this: a zero-length data record copies nothing and falls through to consume_skb(). Mirror that in the read_sock() path by recognizing an empty data record before the actor runs, consuming it, and continuing. Fixes: 662fbcec32f4 ("net/tls: implement ->read_sock()") Signed-off-by: Chuck Lever Reviewed-by: Sabrina Dubroca Link: https://patch.msgid.link/20260630191551.875664-1-cel@kernel.org Signed-off-by: Paolo Abeni

tls: remove dead sockmap (psock) handling from the SW path

2026-06-16T15:55:41+00:00

TLS and sockmap are now mutually exclusive. Try to delete the code from sendmsg and recvmsg path which is now obviously dead. The main goal is to delete enough code for AI security scanners to no longer bother us with sockmap related bugs. At the same time retain the code in case someone has the cycles to fix all of this and make the integration work, again. If the integration does not get restored we can wipe the rest of the skmsg code from TLS in two or three releases. The changes on the Tx side are deeper since that's where most of the bugs are, Rx side simply takes the data from sockmap and gives it to the user. On Tx split record handling and rolling back the iterator were the two problem areas. Reviewed-by: Jakub Sitnicki Reviewed-by: Sabrina Dubroca Link: https://patch.msgid.link/20260614014102.461064-3-kuba@kernel.org Signed-off-by: Jakub Kicinski

tls: reject the combination of TLS and sockmap

2026-06-16T15:55:40+00:00

TLS and sockmap (BPF psock) integration hides a lot of latent bugs. Bugs which may be more or less relevant for real users but they are definitely exploitable. We could not find anyone actively using this integration so let's reject this config. Adding a TLS socket to a sockmap was already rejected by sk_psock_init() through the inet_csk_has_ulp() check. We need to reject the attempts to configure the TLS keys (rather than adding the ULP itself) because checking prior to the ULP installation is tricky without risking a race with sockmap getting added in parallel (sockmap does not hold the socket lock). This patch is a minimal rejection of the feature. Subsequent patch in the series will do a light dead code removal. Full cleanup would require a major rewrite of the Tx path, we don't need skmsg any more. Reviewed-by: Jakub Sitnicki Reviewed-by: Sabrina Dubroca Link: https://patch.msgid.link/20260614014102.461064-2-kuba@kernel.org Signed-off-by: Jakub Kicinski

tls: remove tls_toe and the related driver

2026-06-12T23:43:10+00:00

The tls_toe feature and its single user (chelsio chtls) have been unmaintained for multiple years. It also hooks into the core of the TCP implementation, and bypasses most of the networking stack. Signed-off-by: Sabrina Dubroca Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/1f30e73275c07bf879f547589872d0916025a52e.1781165969.git.sd@queasysnail.net Signed-off-by: Jakub Kicinski