kernel/git/stable/linux.git/fs/nfs, branch linux-rolling-stable

NFS: Prevent resource leak in nfs_alloc_server()

2026-07-04T11:45:09+00:00

commit d189f224308c8ac3feeea8e442c99922bd18f1b2 upstream. It was overlooked to call ida_free() after a failed nfs_alloc_iostats() call. Thus add the missed function call in an if branch. Fixes: 1c7251187dc067a6d460cf33ca67da9c1dd87807 ("NFS: add superblock sysfs entries") Cc: stable@vger.kernel.org Reported-by: Christophe Jaillet Closes: https://lore.kernel.org/linux-nfs/1c8e10c9-def7-4f0d-8aa1-23c8035a38c8@wanadoo.fr/ Signed-off-by: Markus Elfring Signed-off-by: Anna Schumaker Signed-off-by: Greg Kroah-Hartman

NFSv4: clear exception state on successful mkdir retry

2026-07-04T11:45:09+00:00

commit 238e9b51aa29f48b6243212a3b75c8e48d6b96fd upstream. After a server returns NFS4ERR_DELAY for an NFSv4 CREATE issued by mkdir(2), the client correctly waits and retries. When the retry succeeds, however, mkdir(2) can still surface -EEXIST to userspace even though the directory was just created on the server. Reproducer (random 16-hex names so collisions are not the cause) against an in-kernel Linux nfsd; reproduces under both NFSv4.0 and NFSv4.2: N=2000000; base=/var/gdc/export for ((i=1; i<=N; i++)); do d=$base/$(openssl rand -hex 8) mkdir "$d" 2>/dev/null || echo "$(date +%T) failed loop=$i $d" rmdir "$d" 2>/dev/null done Failures cluster at the cadence at which the server-side auth/export cache refresh path causes nfsd to return NFS4ERR_DELAY for CREATE. A wire trace of one failure (the three CREATE RPCs all come from a single mkdir(2), generated by the do-while in nfs4_proc_mkdir()): client -> server CREATE name=... -> NFS4ERR_DELAY ~100 ms later client -> server CREATE name=... -> NFS4_OK (dir created) ~80 us later client -> server CREATE name=... -> NFS4ERR_EXIST (correct) Since commit dd862da61e91 ("nfs: fix incorrect handling of large-number NFS errors in nfs4_do_mkdir()"), nfs4_handle_exception() is called only when _nfs4_proc_mkdir() returned an error. That gate breaks retry-state hygiene: nfs4_do_handle_exception() resets exception.{delay,recovering, retry} to 0 on entry, so calling it on success is what previously cleared the retry flag set by the preceding NFS4ERR_DELAY iteration. With the gate in place, exception.retry stays at 1 after the successful retry, the loop runs once more, and the resulting CREATE for an already-created name yields NFS4ERR_EXIST -> -EEXIST to userspace. Drop the conditional and call nfs4_handle_exception() unconditionally, matching every other do-while in fs/nfs/nfs4proc.c (nfs4_proc_symlink(), nfs4_proc_link(), etc.). The dentry/status separation introduced by that commit is preserved. Fixes: dd862da61e91 ("nfs: fix incorrect handling of large-number NFS errors in nfs4_do_mkdir()") Reported-and-tested-by: Jan Čípa Closes: https://lore.kernel.org/linux-nfs/CA+9S74hSp_tJu2Ffe2BPNC2T25gfkhgjjDkdgSsF5c2rnJq_wA@mail.gmail.com/ Reviewed-by: NeilBrown Cc: stable@vger.kernel.org Signed-off-by: Igor Raits Signed-off-by: Anna Schumaker Signed-off-by: Greg Kroah-Hartman

NFSv4/pNFS: reject zero-length r_addr in nfs4_decode_mp_ds_addr

2026-07-04T11:45:08+00:00

commit 41fe0f7b84f0cb822ae10ab08592996a592b2a25 upstream. nfs4_decode_mp_ds_addr() decodes the r_netid and r_addr opaques of a netaddr4 from a GETDEVICEINFO multipath-DS body, then immediately calls strrchr(buf, '.') to locate the port separator. Both decodes use xdr_stream_decode_string_dup(), and the current code checks only "nlen < 0" / "rlen < 0" before dereferencing the returned string. When the on-wire opaque has length zero, xdr_stream_decode_opaque_inline() returns 0 and xdr_stream_decode_string_dup() falls through to its "*str = NULL; return ret" tail, leaving buf NULL with a return value of 0. The "< 0" check does not catch this, and the next line is strrchr(NULL, '.'), a kernel NULL pointer dereference reachable from any pNFS-flexfile client mounted against a malicious or compromised metadata server. Reject the zero-length cases explicitly so the decoder fails with -EBADMSG (treated as a malformed GETDEVICEINFO body) instead of panicking the client. Cc: stable@vger.kernel.org Fixes: 6b7f3cf96364 ("nfs41: pull decode_ds_addr from file layout to generic pnfs") Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito Signed-off-by: Anna Schumaker Signed-off-by: Greg Kroah-Hartman

NFSv4/flexfiles: reject zero filehandle version count

2026-07-04T11:45:08+00:00

commit 2c6bb3c40bc24f6aa8dfbe6fe98c3ad6389203f2 upstream. ff_layout_alloc_lseg() decodes the filehandle-version array count from the flexfiles layout body. The value is used as the count for kzalloc_objs(), and the current code only rejects NULL. A zero count yields ZERO_SIZE_PTR, which can be stored in dss_info->fh_versions even though later flexfiles paths assume that at least one filehandle version exists. Reject fh_count == 0 before the allocation, matching the existing zero version_count validation in the flexfiles GETDEVICEINFO parser. A QEMU/KASAN run with a malformed flexfiles layout hit: KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:ff_layout_encode_ff_layoutupdate.isra.0+0x15f/0x750 ff_layout_encode_layoutreturn+0x683/0x970 nfs4_xdr_enc_layoutreturn+0x278/0x3a0 Kernel panic - not syncing: Fatal exception The patched kernel rejects the malformed layout without KASAN/oops/panic, and a valid fh_count=1 regression still opens, reads, and unmounts cleanly. Cc: stable@vger.kernel.org Fixes: d67ae825a59d ("pnfs/flexfiles: Add the FlexFile Layout Driver") Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito Signed-off-by: Anna Schumaker Signed-off-by: Greg Kroah-Hartman

pNFS: Fix use-after-free in pnfs_update_layout()

2026-07-04T11:45:06+00:00

commit 13e198a90ca4050f4bee8a3f23680389a6563ccc upstream. When hitting the NFS_LAYOUT_RETURN branch in pnfs_update_layout(), the code calls pnfs_prepare_to_retry_layoutget(lo). If it succeeds, pnfs_put_layout_hdr(lo) is called before trace_pnfs_update_layout(), which still references 'lo'. This results in a use-after-free when the tracepoint accesses lo's fields. Fix this by moving the tracepoint call before pnfs_put_layout_hdr(lo). Fixes: 2c8d5fc37fe2 ("pNFS: Stricter ordering of layoutget and layoutreturn") Cc: stable@vger.kernel.org Signed-off-by: Wentao Liang Signed-off-by: Anna Schumaker Signed-off-by: Greg Kroah-Hartman

NFS: write_completion: dereference loop-local req, not hdr->req

2026-06-02T08:27:45+00:00

5d3869a41f36 ("NFS: fix writeback in presence of errors") introduced a dereference of hdr->req->wb_lock_context in nfs_write_completion's per-request loop. hdr->req is set once at nfs_pgheader_init() time and is not refcount-protected for the lifetime of the loop; when hdr aggregates requests from multiple page groups (common under heavy NFSv3 writeback), a parallel COMMIT on hdr->req's group can drop the last reference and free it while the outer loop is still iterating requests from other groups. KASAN catches this as an 8-byte read at offset +24 of a freed nfs_page slab object (wb_lock_context). All requests in a given pgio share the same open_context, so reading the loop-local req's wb_lock_context yields the same value and is safe -- req is still on hdr->pages and holds its writeback kref through the commit branch. Caught with kasan: BUG: KASAN: slab-use-after-free in nfs_write_completion+0x8f8/0xa50 [nfs] Read of size 8 at addr ffff888118af2058 by task kworker/u16:16/122062 CPU: 2 UID: 0 PID: 122062 Comm: kworker/u16:16 Kdump: loaded Not tainted 7.1.0-rc4+ #ge05a759574b2 PREEMPT Workqueue: nfsiod rpc_async_release Call Trace: dump_stack_lvl+0xaf/0x100 ? nfs_write_completion+0x8f8/0xa50 [nfs] print_report+0x157/0x4a1 ? __virt_addr_valid+0x1fb/0x400 ? nfs_write_completion+0x8f8/0xa50 [nfs] kasan_report+0xc2/0x190 ? nfs_write_completion+0x8f8/0xa50 [nfs] nfs_write_completion+0x8f8/0xa50 [nfs] ? nfs_commit_release_pages+0xbd0/0xbd0 [nfs] ? lock_acquire+0x182/0x2e0 ? process_one_work+0x937/0x1890 ? nfs_pgio_header_alloc+0xd0/0xd0 [nfs] rpc_free_task+0xee/0x160 rpc_async_release+0x5d/0xb0 process_one_work+0x9b0/0x1890 ? pwq_dec_nr_in_flight+0xed0/0xed0 ? rpc_final_put_task+0x140/0x140 worker_thread+0x75a/0x10a0 ? process_one_work+0x1890/0x1890 ? kthread+0x1af/0x4d0 ? process_one_work+0x1890/0x1890 kthread+0x3d3/0x4d0 ? kthread_affine_node+0x2c0/0x2c0 ret_from_fork+0x669/0xa50 ? native_tss_update_io_bitmap+0x660/0x660 ? __switch_to+0x9dd/0x1310 ? kthread_affine_node+0x2c0/0x2c0 ret_from_fork_asm+0x11/0x20 Allocated by task 121997 on cpu 3 at 31643.290294s: kasan_save_stack+0x1e/0x40 kasan_save_track+0x13/0x60 __kasan_slab_alloc+0x62/0x70 kmem_cache_alloc_noprof+0x1ab/0x4e0 nfs_page_create+0x152/0x460 [nfs] nfs_page_create_from_folio+0x7e/0x210 [nfs] nfs_update_folio+0x7a9/0x32a0 [nfs] nfs_write_end+0x290/0xc60 [nfs] generic_perform_write+0x4ce/0x990 nfs_file_write+0x6b3/0xce0 [nfs] vfs_write+0x63c/0xfa0 ksys_write+0x122/0x240 do_syscall_64+0xc3/0x13f0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Freed by task 122046 on cpu 0 at 31647.037964s: kasan_save_stack+0x1e/0x40 kasan_save_track+0x13/0x60 kasan_save_free_info+0x37/0x60 __kasan_slab_free+0x3b/0x60 kmem_cache_free+0x11b/0x5a0 nfs_page_group_destroy+0x13a/0x210 [nfs] nfs_unlock_and_release_request+0x64/0x90 [nfs] nfs_commit_release_pages+0x339/0xbd0 [nfs] nfs_commit_release+0x51/0xb0 [nfs] rpc_free_task+0xee/0x160 rpc_async_release+0x5d/0xb0 process_one_work+0x9b0/0x1890 worker_thread+0x75a/0x10a0 kthread+0x3d3/0x4d0 ret_from_fork+0x669/0xa50 ret_from_fork_asm+0x11/0x20 The buggy address belongs to the object at ffff888118af2040\x0a which belongs to the cache nfs_page of size 96 The buggy address is located 24 bytes inside of\x0a freed 96-byte region [ffff888118af2040, ffff888118af20a0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x118af2 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4000000000000040(head|zone=2) page_type: f5(slab) raw: 4000000000000040 ffff88818cf2c4c0 ffffea000e61b990 ffffea0004e7d110 raw: 0000000000000000 0000000800190019 00000000f5000000 0000000000000000 head: 4000000000000040 ffff88818cf2c4c0 ffffea000e61b990 ffffea0004e7d110 head: 0000000000000000 0000000800190019 00000000f5000000 0000000000000000 head: 4000000000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 121997, tgid 121997 (rsync), ts 31643290274577, free_ts 31642154777182 post_alloc_hook+0xd1/0x100 get_page_from_freelist+0xbad/0x2910 __alloc_frozen_pages_noprof+0x1c6/0x4a0 allocate_slab+0x330/0x620 ___slab_alloc+0xe9/0x930 kmem_cache_alloc_noprof+0x35b/0x4e0 nfs_page_create+0x152/0x460 [nfs] nfs_page_create_from_folio+0x7e/0x210 [nfs] nfs_update_folio+0x7a9/0x32a0 [nfs] nfs_write_end+0x290/0xc60 [nfs] generic_perform_write+0x4ce/0x990 nfs_file_write+0x6b3/0xce0 [nfs] vfs_write+0x63c/0xfa0 ksys_write+0x122/0x240 do_syscall_64+0xc3/0x13f0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 page last free pid 122202 tgid 122202 stack trace: __free_frozen_pages+0x6da/0xf30 qlist_free_all+0x53/0x130 kasan_quarantine_reduce+0x198/0x1f0 __kasan_slab_alloc+0x46/0x70 kmem_cache_alloc_noprof+0x1ab/0x4e0 __alloc_object+0x2f/0x230 __create_object+0x22/0x80 kmem_cache_alloc_node_noprof+0x416/0x4d0 __alloc_skb+0x146/0x6e0 tcp_stream_alloc_skb+0x35/0x660 tcp_sendmsg_locked+0x1746/0x4260 tcp_sendmsg+0x2f/0x40 inet_sendmsg+0x9e/0xe0 __sock_sendmsg+0xd9/0x180 sock_sendmsg+0x122/0x200 xprt_sock_sendmsg+0x4ff/0x9a0 Memory state around the buggy address: ffff888118af1f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc ffff888118af1f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888118af2000: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ^ ffff888118af2080: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ffff888118af2100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Reviewed-by Jeff Layton Fixes: 5d3869a41f36 ("NFS: fix writeback in presence of errors") Cc: Olga Kornievskaia Cc: Trond Myklebust Cc: Anna Schumaker Cc: linux-nfs@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Dave Jones Signed-off-by: Trond Myklebust

Merge tag 'nfs-for-7.1-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

2026-04-24T21:20:03+00:00

Pull NFS client updates from Trond Myklebust: "Bugfixes: - Fix handling of ENOSPC so that if we have to resend writes, they are written synchronously - SUNRPC RDMA transport fixes from Chuck - Several fixes for delegated timestamps in NFSv4.2 - Failure to obtain a directory delegation should not cause stat() to fail with NFSv4 - Rename was failing to update timestamps when a directory delegation is held on NFSv4 - Ensure we check rsize/wsize after crossing a NFSv4 filesystem boundary - NFSv4/pnfs: - If the server is down, retry the layout returns on reboot - Fallback to MDS could result in a short write being incorrectly logged Cleanups: - Use memcpy_and_pad in decode_fh" * tag 'nfs-for-7.1-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (21 commits) NFS: Fix RCU dereference of cl_xprt in nfs_compare_super_address NFS: remove redundant __private attribute from nfs_page_class NFSv4.2: fix CLONE/COPY attrs in presence of delegated attributes NFS: fix writeback in presence of errors nfs: use memcpy_and_pad in decode_fh NFSv4.1: Apply session size limits on clone path NFSv4: retry GETATTR if GET_DIR_DELEGATION failed NFS: fix RENAME attr in presence of directory delegations pnfs/flexfiles: validate ds_versions_cnt is non-zero NFS/blocklayout: print each device used for SCSI layouts xprtrdma: Post receive buffers after RPC completion xprtrdma: Scale receive batch size with credit window xprtrdma: Replace rpcrdma_mr_seg with xdr_buf cursor xprtrdma: Decouple frwr_wp_create from frwr_map xprtrdma: Close lost-wakeup race in xprt_rdma_alloc_slot xprtrdma: Avoid 250 ms delay on backlog wakeup xprtrdma: Close sendctx get/put race that can block a transport nfs: update inode ctime after removexattr operation nfs: fix utimensat() for atime with delegated timestamps NFS: improve "Server wrote zero bytes" error ...

NFS: Fix RCU dereference of cl_xprt in nfs_compare_super_address

2026-04-22T12:53:23+00:00

The cl_xprt pointer in struct rpc_clnt is marked as __rcu. Accessing it directly in nfs_compare_super_address() is unsafe and triggers Sparse warnings. Fix this by using rcu_dereference() within an RCU read-side critical section to retrieve the transport pointer. This addresses the sparse warning and ensures atomic access to the pointer, as the transport can be updated via transport switching even while the superblock remains active under sb_lock. Fixes: 7e3fcf61abde ("nfs: don't share mounts between network namespaces") Signed-off-by: Sean Chang Signed-off-by: Trond Myklebust

NFS: remove redundant __private attribute from nfs_page_class

2026-04-22T12:53:23+00:00

The nfs_page_class tracepoint uses a pointer for the 'req' field marked with the __private attribute. This causes Sparse to complain about dereferencing a private pointer within the trace ring buffer context, specifically during the TP_fast_assign() operation. This fixes a Sparse warning introduced in commit b6ef079fd984 ("nfs: more in-depth tracing of writepage events") by removing the redundant __private attribute from the 'req' field. Reviewed-by: Benjamin Coddington Signed-off-by: Sean Chang Signed-off-by: Trond Myklebust

NFSv4.2: fix CLONE/COPY attrs in presence of delegated attributes

2026-04-22T12:53:23+00:00

xfstest generic/407 is failing in 2 ways. It detects that after doing a clone the client does not update it's mtime and it's ctime. CLONE always sends a GETATTR operation and then calls nfs_post_op_update_inode() based on the returned attributes. Because of the delegated attributes the client ignores updating the mtime. Then also, when delegated attributes are present, for the change_attr the server replies with the same values as what the client cached before and thus the generic/407 would flag that. Instead, make sure we invalidate the blocks attr. By adding updating delegated attributes in nfs42_copy_dest_done() both COPY and CLONE would update mtime appropriately. Fixes: e12912d94137 ("NFSv4: Add support for delegated atime and mtime attributes") Signed-off-by: Olga Kornievskaia Signed-off-by: Trond Myklebust