kernel/linux.git/drivers/nvme, branch v6.12.107

nvmet-tcp: Do not WARN on remotely-controlled oversized SGL allocations

2026-08-27T12:32:07+00:00

commit 737a3b535247226f6e1a7988fd9d6e63e7d6fc71 upstream. When fuzzing the nvme target code, I tripped a kernel warning in nvmet_tcp_map_data() because the length passed into the allocator is controlled by the remote initiator. A remote initiator that sends a command with an SGL claiming a huge number, can create a scatterlist and iovec allocation of over 1 million entries, which causes the backing kmalloc call to exceed MAX_PAGE_ORDER and then the page allocator will trip on a WARN_ON_ONCE_GFP() message: WARNING: mm/page_alloc.c:5280 __alloc_frozen_pages_noprof Workqueue: nvmet_tcp_wq nvmet_tcp_io_work ... sgl_alloc_order nvmet_tcp_map_data nvmet_tcp_try_recv_pdu As it's never good to trip a kernel warning remotely due to many systems having panic-on-warn enabled, let's silence it by just add GFP_NOWARN to the allocation flags. Assisted-by: gkh_clanker_2000 Cc: stable Signed-off-by: Greg Kroah-Hartman Signed-off-by: Keith Busch Signed-off-by: Greg Kroah-Hartman

nvmet-tcp: bound SGL data length before allocating command buffers

2026-08-27T12:32:07+00:00

commit 4a3f00262a044e8e15064b1a6860968bf0500bf4 upstream. nvmet_tcp_map_data() reads the host-controlled 32-bit sgl->length and, for the in-capsule offset descriptor (type 0x01), checks it against port->inline_data_size before use. Any other SGL descriptor type -- including the non-inline transport SGL data-block descriptor (type (NVME_TRANSPORT_SGL_DATA_DESC << 4) | NVME_SGL_FMT_TRANSPORT_A, the type a real host uses for out-of-capsule writes) skips that check entirely and falls straight through to: cmd->req.sg = sgl_alloc(len, GFP_KERNEL, &cmd->req.sg_cnt); with len taken directly from the wire, unbounded up to 4 GiB. nvmet_req_init() only parses the command and never inspects sgl->length, and nvmet_check_transfer_len() -- the only other place transfer_len is validated -- runs later, from req->execute(), after the allocation has already happened. For a write command the target responds with an R2T and parks the command waiting for the host to send the data; if the host (or an unauthenticated peer that simply never follows up) never does, the sgl_alloc() buffer stays resident for the life of the command. NVMe/TCP has no mandatory authentication in the default configuration, so any peer able to reach the target portal and complete a Fabrics connect can drive this with a single crafted command, repeatable across queues and connections for amplification. This is unbounded kernel memory allocation triggered by a remote, effectively unauthenticated peer. Validate len against the same NVMET_TCP_MAXH2CDATA ceiling this file already uses to bound per-PDU H2C data, for every SGL descriptor type, before doing any allocation. This closes the gap for the non-inline descriptor while leaving the existing, tighter inline_data_size check in place for the in-capsule case. Runtime-verified on a v6.19 KASAN stand: with this bound in place, a crafted write command carrying an oversized non-inline SGL length is rejected before sgl_alloc() runs, where the same request previously drove an unbounded ~256 MiB kernel allocation (up to 4 GiB) that stayed resident pending an R2T the host never satisfies. Fixes: 872d26a391da ("nvmet-tcp: add NVMe over TCP target driver") Cc: stable@vger.kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Ibrahim Hashimov Assisted-by: AuditCode-AI:2026.07 Signed-off-by: Keith Busch Signed-off-by: Greg Kroah-Hartman

nvmet-fc: fix invalid free in LS IOD error path

2026-08-27T12:32:07+00:00

commit ba98d6796d12258e837ece065d2ecb59d76ce4ff upstream. nvmet_fc_alloc_ls_iodlist() advances iod while initializing the LS IOD array. If an rqstbuf allocation or response buffer DMA mapping fails, the unwind loop decrements iod past the start of the array. The final kfree(iod) therefore frees an address before the allocated object. This can be reproduced with nvme-fcloop and failslab by setting fail-nth to 6 before creating a target port. KASAN reports: BUG: KASAN: invalid-free in nvmet_fc_register_targetport Free of addr ffff88816cf8ff48 by task nvmet_fail_nth/9552 Free the original allocation base stored in tgtport->iod instead. With this fix applied, the same sysfs write with fail-nth=6 returns -ENOMEM without any KASAN report. Fixes: c53432030d86 ("nvme-fabrics: Add target support for FC transport") Cc: stable@vger.kernel.org Reviewed-by: Maurizio Lombardi Assisted-by: Codex:gpt-5 Signed-off-by: Jiang HongHui Signed-off-by: Keith Busch Signed-off-by: Greg Kroah-Hartman

nvmet-auth: zero the AUTH_RECEIVE response buffer

2026-08-27T12:32:07+00:00

commit 3ddcfb013322aa37eaa7a0d344b73079c38dfa21 upstream. nvmet_execute_auth_receive() allocates the response buffer with kmalloc() sized by the host-supplied AUTH_RECEIVE allocation length, but the DH-HMAC-CHAP builders write only a fixed-size message into it. The full allocation length is then copied to the wire by nvmet_copy_to_sgl(), so a remote initiator receives the bytes past the built message -- up to nearly a page of uninitialized slab -- during the pre-authentication handshake. Allocate the buffer with kzalloc() so the unwritten tail is zeroed before it is sent; conforming responses are unaffected. Fixes: db1312dd9548 ("nvmet: implement basic In-Band Authentication") Cc: stable@vger.kernel.org Signed-off-by: Bryam Vargas Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch Signed-off-by: Greg Kroah-Hartman

nvmet-auth: reject short AUTH_RECEIVE buffers

2026-08-03T09:17:34+00:00

[ Upstream commit 779575bc35c687697ba69e904f2cd22e60112534 ] nvmet_execute_auth_receive() trusts the AUTH_RECEIVE allocation length after checking only that it is nonzero and matches the transfer length. In the SUCCESS1 and FAILURE1/default states, that lets a remote NVMe-oF initiator reach the fixed-size DH-HMAC-CHAP response builders with a kmalloc() buffer shorter than the response, so nvmet_auth_success1() and nvmet_auth_failure1() write past the allocation; both only WARN_ON the short length and then format the message anyway. Impact: A remote NVMe-oF initiator with access to an auth-enabled target can trigger a 16-byte heap out-of-bounds write via a one-byte AUTH_RECEIVE allocation length. Compute the minimum response length for the current DH-HMAC-CHAP step in nvmet_auth_receive_data_len() and report a zero data length when the host-supplied allocation length is shorter, so the existing zero-length check in nvmet_execute_auth_receive() rejects the command before any builder runs. The SUCCESS1 minimum is sizeof(struct nvmf_auth_dhchap_success1_data) plus the HMAC hash length, because the response hash is written into the rval[] flexible-array tail, so the minimum is state dependent rather than a flat sizeof. CHALLENGE keeps its existing variable-length guard in nvmet_auth_challenge(). This is reachable only when in-band DH-HMAC-CHAP authentication is configured on the target. Fixes: db1312dd9548 ("nvmet: implement basic In-Band Authentication") Cc: stable@vger.kernel.org Assisted-by: Codex:gpt-5-5-xhigh Assisted-by: Claude:claude-opus-4-8 Reviewed-by: Hannes Reinecke Signed-off-by: Michael Bommarito Signed-off-by: Keith Busch Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

nvmet: Introduce nvmet_req_transfer_len()

2026-08-03T09:17:34+00:00

[ Upstream commit 43043c9b97258a008b3402cfbbf1c5d82151c77f ] Add the new function nvmet_req_transfer_len() to parse a request command to extract the transfer length of the command. This function implementation relies on multiple helper functions for parsing I/O commands (nvmet_io_cmd_transfer_len()), admin commands (nvmet_admin_cmd_data_len()) and fabrics connect commands (nvmet_connect_cmd_data_len). Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Tested-by: Rick Wertenbroek Tested-by: Manivannan Sadhasivam Signed-off-by: Keith Busch Stable-dep-of: 779575bc35c6 ("nvmet-auth: reject short AUTH_RECEIVE buffers") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

nvmet-rdma: handle inline data with a nonzero offset

2026-07-24T14:11:37+00:00

commit 48c0162f647bb47e6084ffbc71b8f213f5e2f4f8 upstream. nvmet_rdma_use_inline_sg() maps the host-controlled inline data offset into the per-command inline scatterlist. The bounds check admits any offset with off + len <= inline_data_size, but the mapping still assumes the data begins in the first inline page: sg->offset = off; sg->length = min_t(int, len, PAGE_SIZE - off); When a port is configured with inline_data_size > PAGE_SIZE (settable up to max(SZ_16K, PAGE_SIZE)), an offset in (PAGE_SIZE, inline_data_size] makes "PAGE_SIZE - off" underflow, so sg->length is set to ~4 GiB and the block backend reads far past the first inline page. num_pages(len) also ignores the offset, so an in-bounds offset whose [off, off+len) span crosses a page boundary under-counts the scatterlist. Map the offset properly: split it into a page index and an in-page offset, start the scatterlist at that page, and size the page count from page_off + len. Because the request scatterlist may now start at inline_sg[page_idx] rather than inline_sg[0], generalize the inline-SGL identity test in nvmet_rdma_release_rsp() to a range test; otherwise the persistent inline scatterlist is mistaken for an allocated one and nvmet_req_free_sgls() frees an inline page (and warns in free_large_kmalloc()). Fixes: 0d5ee2b2ab4f ("nvmet-rdma: support max(16KB, PAGE_SIZE) inline data") Cc: stable@vger.kernel.org Suggested-by: Keith Busch Reported-by: Bryam Vargas Signed-off-by: Bryam Vargas Signed-off-by: Keith Busch Signed-off-by: Greg Kroah-Hartman

nvme-multipath: fix flex array size in struct nvme_ns_head

2026-07-24T14:10:50+00:00

[ Upstream commit 001e57554de81aa79c25c18fd53911d8a415c304 ] struct nvme_ns_head contains a flexible array member, current_path[], which is indexed using the NUMA node ID: head->current_path[numa_node_id()] The structure is currently allocated as: size = sizeof(struct nvme_ns_head) + (num_possible_nodes() * sizeof(struct nvme_ns *)); head = kzalloc(size, GFP_KERNEL); This allocation assumes that NUMA node IDs are sequential and densely packed from 0 .. num_possible_nodes() - 1. While this assumption holds on many systems, it is not always true on some architectures such as powerpc. On some powerpc systems, NUMA node IDs can be sparse. For example: NUMA: NUMA node(s): 6 NUMA node0 CPU(s): 80-159 NUMA node8 CPU(s): 0-79 NUMA node252 CPU(s): NUMA node253 CPU(s): NUMA node254 CPU(s): NUMA node255 CPU(s): That is, the possible/online NUMA node IDs are: 0, 8, 252, 253, 254, 255 In this case: num_possible_nodes() = 6 So memory is allocated for only 6 entries in current_path[]. However, the array is later indexed using the actual NUMA node ID. As a result, accesses such as: head->current_path[8] or head->current_path[252] goes out of bounds, leading to the following KASAN splat: ================================================================== BUG: KASAN: slab-out-of-bounds in nvme_mpath_revalidate_paths+0x22c/0x290 [nvme_core] Write of size 8 at addr c00020003bda35b8 by task kworker/u641:2/1997 CPU: 1 UID: 0 PID: 1997 Comm: kworker/u641:2 Not tainted 7.1.0-rc5-dirty #14 PREEMPT(lazy) Hardware name: 8335-GTH POWER9 0x4e1202 opal:skiboot-v6.5.3-35-g1851b2a06 PowerNV Workqueue: async async_run_entry_fn Call Trace: [c000200037fa7510] [c0000000021c23d4] dump_stack_lvl+0x88/0xdc (unreliable) [c000200037fa7540] [c0000000009fda90] print_report+0x22c/0x67c [c000200037fa7630] [c0000000009fd508] kasan_report+0x108/0x220 [c000200037fa7740] [c0000000009fff48] __asan_store8+0xe8/0x120 [c000200037fa7760] [c008000018e76474] nvme_mpath_revalidate_paths+0x22c/0x290 [nvme_core] [c000200037fa7800] [c008000018e6556c] nvme_update_ns_info+0x4a4/0x5e0 [nvme_core] [c000200037fa7a50] [c008000018e66270] nvme_alloc_ns+0x6d8/0x1a70 [nvme_core] [c000200037fa7c20] [c008000018e679fc] nvme_scan_ns+0x3f4/0x630 [nvme_core] [c000200037fa7d10] [c00000000031f22c] async_run_entry_fn+0x9c/0x3a0 [c000200037fa7db0] [c0000000002fa544] process_one_work+0x414/0xa10 [c000200037fa7ec0] [c0000000002fbf00] worker_thread+0x320/0x640 [c000200037fa7f80] [c00000000030d0f8] kthread+0x278/0x290 [c000200037fa7fe0] [c00000000000ded8] start_kernel_thread+0x14/0x18 Allocated by task 1997 on cpu 1 at 35.928317s: The buggy address belongs to the object at c00020003bda3000 which belongs to the cache kmalloc-rnd-15-2k of size 2048 The buggy address is located 16 bytes to the right of allocated 1448-byte region [c00020003bda3000, c00020003bda35a8) The buggy address belongs to the physical page: Memory state around the buggy address: c00020003bda3480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c00020003bda3500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >c00020003bda3580: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ c00020003bda3600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc c00020003bda3680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Fix this by allocating the flexible array using nr_node_ids instead of num_possible_nodes(). Since nr_node_ids represents the maximum possible NUMA node IDs, indexing current_path[] using numa_node_id() becomes safe even on systems with sparse node IDs. Fixes: f333444708f8 ("nvme: take node locality into account when selecting a path") Tested-by: Mukesh Kumar Chaurasiya (IBM) Reviewed-by: Mukesh Kumar Chaurasiya (IBM) Reviewed-by: Hannes Reinecke Reviewed-by: John Garry Reviewed-by: Christoph Hellwig Signed-off-by: Nilay Shroff Signed-off-by: Keith Busch Signed-off-by: Sasha Levin

nvmet-tcp: fix page fragment cache leak in error path

2026-07-24T14:10:50+00:00

[ Upstream commit 4dae393956093c807212918fd91a8fc70df15338 ] In nvmet_tcp_alloc_queue(), when a connection is closed during the allocation process (e.g., nvmet_tcp_set_queue_sock() returns -ENOTCONN), the error handling jumps to out_destroy_sq and then to out_ida_remove without draining the page fragment cache. Although nvmet_tcp_free_cmd() is called in some error paths to release individual page fragments, the underlying page cache reference held by queue->pf_cache is never released. The first allocation using pf_cache is the call to nvmet_tcp_alloc_cmd() for queue->connect, which happens after ida_alloc() returns successfully. This results in a page leak each time a connection fails during allocation, which could lead to memory exhaustion over time if connections are repeatedly opened and closed. Fix this by calling page_frag_cache_drain() before freeing the queue structure in the out_ida_remove label. Fixes: 872d26a391da ("nvmet-tcp: add NVMe over TCP target driver") Reviewed-by: Christoph Hellwig Signed-off-by: Geliang Tang Signed-off-by: Keith Busch Signed-off-by: Sasha Levin

nvmet-tcp: Fix potential UAF when ddgst mismatch

2026-07-24T14:10:40+00:00

commit dbbd07d0a7020b80f6a7028e561908f7b83b3d5a upstream. Shivam Kumar found via vulnerability testing: When data digest is enabled on an NVMe/TCP connection and a digest mismatch occurs on a non-final H2C_DATA PDU during an R2T-based data transfer, the digest error handler in nvmet_tcp_try_recv_ddgst() calls nvmet_req_uninit() — which performs percpu_ref_put() on the submission queue — but does NOT mark the command as completed. It does not set cqe->status, does not modify rbytes_done, and does not clear any flag. When the subsequent fatal error triggers queue teardown, nvmet_tcp_uninit_data_in_cmds() iterates all commands, checks nvmet_tcp_need_data_in() for each one, and finds that the already-uninited command still appears to need data (because rbytes_done < transfer_len and cqe->status == 0). It therefore calls nvmet_req_uninit() a second time on the same command — a double percpu_ref_put against a single percpu_ref_get. Reported-by: Shivam Kumar Reviewed-by: Christoph Hellwig Signed-off-by: Sagi Grimberg Signed-off-by: Keith Busch Signed-off-by: Greg Kroah-Hartman