kernel/linux.git/net/tls, branch v6.6.152

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

2026-08-19T16:13:13+00:00

commit 7bca91d63341274e857f4aeaad54d229405e93dc upstream. 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 Signed-off-by: Greg Kroah-Hartman

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

2026-08-19T16:13:08+00:00

[ Upstream commit af0e5cdd031f4f4a8f6d4160bfbda4f36872b0ed ] 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 Signed-off-by: Sasha Levin

tls: device: push pending open record on splice EOF

2026-08-03T09:15:20+00:00

[ Upstream commit eaa39f9f8ac8c1d032cd26b9cd572804e9d7683f ] 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 Signed-off-by: Sasha Levin

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

2026-07-24T14:03:28+00:00

[ Upstream commit 3be28e2c9cd0230cb51fd4967df095273afd3848 ] 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 Signed-off-by: Sasha Levin

net: skmsg: preserve sg.copy across SG transforms

2026-07-04T11:42:25+00:00

commit 406e8a651a7b854c41fecd5117bb282b3a6c2c6b upstream. The sk_msg sg.copy bitmap is part of the scatterlist entry ownership state. A set bit tells sk_msg_compute_data_pointers() not to expose the entry through writable BPF ctx->data. This protects entries backed by pages that are not private to the sk_msg, such as splice-backed file page-cache pages. Several sk_msg transform paths move, copy, split, or compact msg->sg.data[] entries without moving the matching sg.copy bit. This can make an externally backed entry arrive at a new slot with a clear copy bit. A later SK_MSG verdict can then expose sg_virt(sge) as writable ctx->data and BPF stores can modify the original page cache. Keep sg.copy synchronized with sg.data[] whenever entries are transferred, shifted, split, or copied into a new sk_msg. Clear the bit when an entry is replaced by a newly allocated private page or freed. This covers the BPF pull/push/pop helpers, sk_msg_shift_left/right(), sk_msg_xfer(), and tls_split_open_record(), including the partial tail entry created during TLS open-record splitting. Fixes: d3b18ad31f93 ("tls: add bpf support to sk_msg handling") Cc: stable@vger.kernel.org Reported-by: Yiming Qian Reported-by: Keenan Dong Signed-off-by: Yiming Qian Link: https://patch.msgid.link/20260610062137.49075-1-yimingqian591@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

tls: Preserve sk_err across recvmsg() when data has been copied

2026-06-01T15:43:13+00:00

[ Upstream commit f508262ae9f21fe0e6c0749948b9dc7dd5a62a70 ] The sk_err check in tls_rx_rec_wait() consumes the error via sock_error(), which clears sk_err atomically. When the caller (tls_sw_recvmsg, tls_sw_splice_read, or tls_sw_read_sock) already has bytes copied to userspace, it returns those bytes and discards the error from this call. sk_err is now zero on the socket, so the next read syscall observes only RCV_SHUTDOWN and reports a clean EOF instead of the actual error (typically -ECONNRESET). The race is reachable when tls_read_flush_backlog()'s periodic sk_flush_backlog() triggers tcp_reset() in the middle of a multi-record read. Pass a has_copied flag to tls_rx_rec_wait(). When has_copied is false, consume sk_err via sock_error() as before. When has_copied is true, report the error from READ_ONCE() but leave sk_err set: the caller returns the byte count and discards the err from this call, and the next read syscall surfaces the preserved sk_err. This mirrors the tcp_recvmsg() preserve-and-surface pattern. The decrypt-abort path is unaffected: tls_err_abort() raises sk_err to EBADMSG after tls_rx_rec_wait() returns, and nothing on the caller's return path consumes it, so the EBADMSG surfaces on the next read. tls_sw_splice_read() passes has_copied=false: it processes one record per call, so no bytes have been copied within the function when tls_rx_rec_wait() runs. A reset that arrives between iterations of splice_direct_to_actor() (the sendfile() path) is still consumed by sock_error() in the later call, and the outer loop returns the prior iterations' byte count and drops the error. tcp_splice_read() exhibits the same pattern at the iteration boundary; addressing it belongs at the splice_direct_to_actor() layer and is out of scope here. Fixes: c46b01839f7a ("tls: rx: periodically flush socket backlog") Suggested-by: Jakub Kicinski Signed-off-by: Chuck Lever Link: https://patch.msgid.link/20260513125825.205189-1-cel@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: tls: prevent chain-after-chain in plain text SG

2026-06-01T15:43:13+00:00

[ Upstream commit ff26a0e8377dec07e4a7230db7675bed1b9a6d03 ] Sashiko points out that if end = 0 (start != 0) the current code will create a chain link to content type right after the wrap link: This would create a chain where the wrap link points directly to another chain link. The scatterlist API sg_next iterator does not recursively resolve consecutive chain links. meaning this is illegal input to crypto. The wrapping link is unnecessary if end = 0. end is the entry after the last one used so end = 0 means there's nothing pushed after the wrap: end start i v v v [ ]...[ ][ d ][ d ][ d ][ d ][rsv for wrap] Skip the wrapping in this case. TLS 1.3 can use the "wrapping slot" for it's chaining if end = 0. This avoids the chain-after-chain. Move the wrap chaining before marking END and chaining off content type, that feels like more logical ordering to me, but should not matter from functional perspective. Reported-by: Sashiko Fixes: 9aaaa56845a0 ("bpf: Sockmap/tls, skmsg can have wrapped skmsg that needs extra chaining") Signed-off-by: Jakub Kicinski Link: https://patch.msgid.link/20260511174920.433155-3-kuba@kernel.org Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: tls: fix off-by-one in sg_chain entry count for wrapped sk_msg ring

2026-06-01T15:43:13+00:00

[ Upstream commit 285943c6e7ca309bbea84b253745154241d9788a ] When an sk_msg scatterlist ring wraps (sg.end < sg.start), tls_push_record() chains the tail portion of the ring to the head using sg_chain(). An extra entry in the sg array is reserved for this: struct sk_msg_sg { [...] /* The extra two elements: * 1) used for chaining the front and sections when the list becomes * partitioned (e.g. end < start). The crypto APIs require the * chaining; * 2) to chain tailer SG entries after the message. */ struct scatterlist data[MAX_MSG_FRAGS + 2]; The current code uses MAX_SKB_FRAGS + 1 as the ring size: sg_chain(&msg_pl->sg.data[msg_pl->sg.start], MAX_SKB_FRAGS - msg_pl->sg.start + 1, msg_pl->sg.data); This places the chain pointer at sg_chain(data[start], (MAX_SKB_FRAGS - msg_start + 1) .. = &data[start] + (MAX_SKB_FRAGS - msg_start + 1) - 1 = data[start + (MAX_SKB_FRAGS - start + 1) - 1] = data[MAX_SKB_FRAGS] instead of the true last entry. This is likely due to a "race" of the commit under Fixes landing close to commit 031097d9e079 ("bpf: sk_msg, zap ingress queue on psock down") Convert to ARRAY_SIZE and drop the data[start] / - start (as suggested by Sabrina). Reported-by: 钱一铭 Fixes: 9aaaa56845a0 ("bpf: Sockmap/tls, skmsg can have wrapped skmsg that needs extra chaining") Signed-off-by: Jakub Kicinski Reviewed-by: Sabrina Dubroca Link: https://patch.msgid.link/20260511174920.433155-2-kuba@kernel.org Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: tls: fix strparser anchor skb leak on offload RX setup failure

2026-05-23T11:03:31+00:00

[ Upstream commit 58689498ca3384851145a754dbb1d8ed1cf9fb54 ] When tls_set_device_offload_rx() fails at tls_dev_add(), the error path calls tls_sw_free_resources_rx() to clean up the SW context that was initialized by tls_set_sw_offload(). This function calls tls_sw_release_resources_rx() (which stops the strparser via tls_strp_stop()) and tls_sw_free_ctx_rx() (which kfrees the context), but never frees the anchor skb that was allocated by alloc_skb(0) in tls_strp_init(). Note that tls_sw_free_resources_rx() is exclusively used for this "failed to start offload" code path, there's no other caller. The leak did not exist before commit 84c61fe1a75b ("tls: rx: do not use the standard strparser"), because the standard strparser doesn't try to pre-allocate an skb. The normal close path in tls_sk_proto_close() handles cleanup by calling tls_sw_strparser_done() (which calls tls_strp_done()) after dropping the socket lock, because tls_strp_done() does cancel_work_sync() and the strparser work handler takes the socket lock. Fixes: 84c61fe1a75b ("tls: rx: do not use the standard strparser") Signed-off-by: Jakub Kicinski Reviewed-by: Vadim Fedorenko Link: https://patch.msgid.link/20260428231559.1358502-1-kuba@kernel.org Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net/tls: fix use-after-free in -EBUSY error path of tls_do_encryption

2026-04-18T08:39:51+00:00

commit a9b8b18364fffce4c451e6f6fd218fa4ab646705 upstream. The -EBUSY handling in tls_do_encryption(), introduced by commit 859054147318 ("net: tls: handle backlogging of crypto requests"), has a use-after-free due to double cleanup of encrypt_pending and the scatterlist entry. When crypto_aead_encrypt() returns -EBUSY, the request is enqueued to the cryptd backlog and the async callback tls_encrypt_done() will be invoked upon completion. That callback unconditionally restores the scatterlist entry (sge->offset, sge->length) and decrements ctx->encrypt_pending. However, if tls_encrypt_async_wait() returns an error, the synchronous error path in tls_do_encryption() performs the same cleanup again, double-decrementing encrypt_pending and double-restoring the scatterlist. The double-decrement corrupts the encrypt_pending sentinel (initialized to 1), making tls_encrypt_async_wait() permanently skip the wait for pending async callbacks. A subsequent sendmsg can then free the tls_rec via bpf_exec_tx_verdict() while a cryptd callback is still pending, resulting in a use-after-free when the callback fires on the freed record. Fix this by skipping the synchronous cleanup when the -EBUSY async wait returns an error, since the callback has already handled encrypt_pending and sge restoration. Fixes: 859054147318 ("net: tls: handle backlogging of crypto requests") Cc: stable@vger.kernel.org Signed-off-by: Muhammad Alifa Ramdhan Reviewed-by: Sabrina Dubroca Link: https://patch.msgid.link/20260403013617.2838875-1-ramdhan@starlabs.sg Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman