kernel.git/fs/nfsd, branch linux-6.15.y

NFSD: detect mismatch of file handle and delegation stateid in OPEN op

2025-08-20T16:35:44Z

commit 9c65001c57164033ad08b654c8b5ae35512ddf4a upstream. When the client sends an OPEN with claim type CLAIM_DELEG_CUR_FH or CLAIM_DELEGATION_CUR, the delegation stateid and the file handle must belong to the same file, otherwise return NFS4ERR_INVAL. Note that RFC8881, section 8.2.4, mandates the server to return NFS4ERR_BAD_STATEID if the selected table entry does not match the current filehandle. However returning NFS4ERR_BAD_STATEID in the OPEN causes the client to retry the operation and therefor get the client into a loop. To avoid this situation we return NFS4ERR_INVAL instead. Reported-by: Petro Pavlov Fixes: c44c5eeb2c02 ("[PATCH] nfsd4: add open state code for CLAIM_DELEGATE_CUR") Cc: stable@vger.kernel.org Signed-off-by: Dai Ngo Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman

nfsd: handle get_client_locked() failure in nfsd4_setclientid_confirm()

2025-08-20T16:35:44Z

commit 908e4ead7f757504d8b345452730636e298cbf68 upstream. Lei Lu recently reported that nfsd4_setclientid_confirm() did not check the return value from get_client_locked(). a SETCLIENTID_CONFIRM could race with a confirmed client expiring and fail to get a reference. That could later lead to a UAF. Fix this by getting a reference early in the case where there is an extant confirmed client. If that fails then treat it as if there were no confirmed client found at all. In the case where the unconfirmed client is expiring, just fail and return the result from get_client_locked(). Reported-by: lei lu Closes: https://lore.kernel.org/linux-nfs/CAEBF3_b=UvqzNKdnfD_52L05Mqrqui9vZ2eFamgAbV0WG+FNWQ@mail.gmail.com/ Fixes: d20c11d86d8f ("nfsd: Protect session creation and client confirm using client_lock") Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman

nfsd: avoid ref leak in nfsd_open_local_fh()

2025-08-15T10:17:03Z

commit e5a73150776f18547ee685c9f6bfafe549714899 upstream. If two calls to nfsd_open_local_fh() race and both successfully call nfsd_file_acquire_local(), they will both get an extra reference to the net to accompany the file reference stored in *pnf. One of them will fail to store (using xchg()) the file reference in *pnf and will drop that reference but WON'T drop the accompanying reference to the net. This leak means that when the nfs server is shut down it will hang in nfsd_shutdown_net() waiting for &nn->nfsd_net_free_done. This patch adds the missing nfsd_net_put(). Reported-by: Mike Snitzer Fixes: e6f7e1487ab5 ("nfs_localio: simplify interface to nfsd for getting nfsd_file") Cc: stable@vger.kernel.org Signed-off-by: NeilBrown Tested-by: Mike Snitzer Reviewed-by: Mike Snitzer Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman

nfsd: don't set the ctime on delegated atime updates

2025-08-15T10:17:03Z

commit f9a348e0de19226fc3c7e81de7677d3fa2c4b2d8 upstream. Clients will typically precede a DELEGRETURN for a delegation with delegated timestamp with a SETATTR to set the timestamps on the server to match what the client has. knfsd implements this by using the nfsd_setattr() infrastructure, which will set ATTR_CTIME on any update that goes to notify_change(). This is problematic as it means that the client will get a spurious ctime update when updating the atime. POSIX unfortunately doesn't phrase it succinctly, but updating the atime due to reads should not update the ctime. In this case, the client is sending a SETATTR to update the atime on the server to match its latest value. The ctime should not be advanced in this case as that would incorrectly indicate a change to the inode. Fix this by not implicitly setting ATTR_CTIME when ATTR_DELEG is set in __nfsd_setattr(). The decoder for FATTR4_WORD2_TIME_DELEG_MODIFY already sets ATTR_CTIME, so this is sufficient to make it skip setting the ctime on atime-only updates. Fixes: 7e13f4f8d27d ("nfsd: handle delegated timestamps in SETATTR") Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman

nfsd: use threads array as-is in netlink interface

2025-06-27T10:13:36Z

commit 8ea688a3372e8369dc04395b39b4e71a6d91d4d5 upstream. The old nfsdfs interface for starting a server with multiple pools handles the special case of a single entry array passed down from userland by distributing the threads over every NUMA node. The netlink control interface however constructs an array of length nfsd_nrpools() and fills any unprovided slots with 0's. This behavior defeats the special casing that the old interface relies on. Change nfsd_nl_threads_set_doit() to pass down the array from userland as-is. Fixes: 7f5c330b2620 ("nfsd: allow passing in array of thread counts via netlink") Cc: stable@vger.kernel.org Reported-by: Mike Snitzer Closes: https://lore.kernel.org/linux-nfs/aDC-ftnzhJAlwqwh@kernel.org/ Signed-off-by: Jeff Layton Reviewed-by: Simon Horman Tested-by: Mike Snitzer Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman

nfsd: Initialize ssc before laundromat_work to prevent NULL dereference

2025-06-27T10:12:57Z

commit b31da62889e6d610114d81dc7a6edbcaa503fcf8 upstream. In nfs4_state_start_net(), laundromat_work may access nfsd_ssc through nfs4_laundromat -> nfsd4_ssc_expire_umount. If nfsd_ssc isn't initialized, this can cause NULL pointer dereference. Normally the delayed start of laundromat_work allows sufficient time for nfsd_ssc initialization to complete. However, when the kernel waits too long for userspace responses (e.g. in nfs4_state_start_net -> nfsd4_end_grace -> nfsd4_record_grace_done -> nfsd4_cld_grace_done -> cld_pipe_upcall -> __cld_pipe_upcall -> wait_for_completion path), the delayed work may start before nfsd_ssc initialization finishes. Fix this by moving nfsd_ssc initialization before starting laundromat_work. Fixes: f4e44b393389 ("NFSD: delay unmount source's export after inter-server copy completed.") Cc: stable@vger.kernel.org Reviewed-by: Jeff Layton Signed-off-by: Li Lingfeng Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman

nfsd: nfsd4_spo_must_allow() must check this is a v4 compound request

2025-06-27T10:12:57Z

commit 1244f0b2c3cecd3f349a877006e67c9492b41807 upstream. If the request being processed is not a v4 compound request, then examining the cstate can have undefined results. This patch adds a check that the rpc procedure being executed (rq_procinfo) is the NFSPROC4_COMPOUND procedure. Reported-by: Olga Kornievskaia Cc: stable@vger.kernel.org Reviewed-by: Jeff Layton Signed-off-by: NeilBrown Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman

nfsd: fix access checking for NLM under XPRTSEC policies

2025-06-27T10:12:57Z

commit 0813c5f01249dbc32ccbc68d27a24fde5bf2901c upstream. When an export policy with xprtsec policy is set with "tls" and/or "mtls", but an NFS client is doing a v3 xprtsec=tls mount, then NLM locking calls fail with an error because there is currently no support for NLM with TLS. Until such support is added, allow NLM calls under TLS-secured policy. Fixes: 4cc9b9f2bf4d ("nfsd: refine and rename NFSD_MAY_LOCK") Cc: stable@vger.kernel.org Signed-off-by: Olga Kornievskaia Reviewed-by: NeilBrown Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman

NFSD: Implement FATTR4_CLONE_BLKSIZE attribute

2025-06-27T10:12:57Z

commit d6ca7d2643eebe09cf46840bdc7d68b6e07aba77 upstream. RFC 7862 states that if an NFS server implements a CLONE operation, it MUST also implement FATTR4_CLONE_BLKSIZE. NFSD implements CLONE, but does not implement FATTR4_CLONE_BLKSIZE. Note that in Section 12.2, RFC 7862 claims that FATTR4_CLONE_BLKSIZE is RECOMMENDED, not REQUIRED. Likely this is because a minor version is not permitted to add a REQUIRED attribute. Confusing. We assume this attribute reports a block size as a count of bytes, as RFC 7862 does not specify a unit. Reported-by: Roland Mainz Suggested-by: Christoph Hellwig Reviewed-by: Roland Mainz Cc: stable@vger.kernel.org # v6.7+ Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman

NFSD: fix race between nfsd registration and exports_proc

2025-06-27T10:12:57Z

commit f7fb730cac9aafda8b9813b55d04e28a9664d17c upstream. As of now nfsd calls create_proc_exports_entry() at start of init_nfsd and cleanup by remove_proc_entry() at last of exit_nfsd. Which causes kernel OOPs if there is race between below 2 operations: (i) exportfs -r (ii) mount -t nfsd none /proc/fs/nfsd for 5.4 kernel ARM64: CPU 1: el1_irq+0xbc/0x180 arch_counter_get_cntvct+0x14/0x18 running_clock+0xc/0x18 preempt_count_add+0x88/0x110 prep_new_page+0xb0/0x220 get_page_from_freelist+0x2d8/0x1778 __alloc_pages_nodemask+0x15c/0xef0 __vmalloc_node_range+0x28c/0x478 __vmalloc_node_flags_caller+0x8c/0xb0 kvmalloc_node+0x88/0xe0 nfsd_init_net+0x6c/0x108 [nfsd] ops_init+0x44/0x170 register_pernet_operations+0x114/0x270 register_pernet_subsys+0x34/0x50 init_nfsd+0xa8/0x718 [nfsd] do_one_initcall+0x54/0x2e0 CPU 2 : Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 PC is at : exports_net_open+0x50/0x68 [nfsd] Call trace: exports_net_open+0x50/0x68 [nfsd] exports_proc_open+0x2c/0x38 [nfsd] proc_reg_open+0xb8/0x198 do_dentry_open+0x1c4/0x418 vfs_open+0x38/0x48 path_openat+0x28c/0xf18 do_filp_open+0x70/0xe8 do_sys_open+0x154/0x248 Sometimes it crashes at exports_net_open() and sometimes cache_seq_next_rcu(). and same is happening on latest 6.14 kernel as well: [ 0.000000] Linux version 6.14.0-rc5-next-20250304-dirty ... [ 285.455918] Unable to handle kernel paging request at virtual address 00001f4800001f48 ... [ 285.464902] pc : cache_seq_next_rcu+0x78/0xa4 ... [ 285.469695] Call trace: [ 285.470083] cache_seq_next_rcu+0x78/0xa4 (P) [ 285.470488] seq_read+0xe0/0x11c [ 285.470675] proc_reg_read+0x9c/0xf0 [ 285.470874] vfs_read+0xc4/0x2fc [ 285.471057] ksys_read+0x6c/0xf4 [ 285.471231] __arm64_sys_read+0x1c/0x28 [ 285.471428] invoke_syscall+0x44/0x100 [ 285.471633] el0_svc_common.constprop.0+0x40/0xe0 [ 285.471870] do_el0_svc_compat+0x1c/0x34 [ 285.472073] el0_svc_compat+0x2c/0x80 [ 285.472265] el0t_32_sync_handler+0x90/0x140 [ 285.472473] el0t_32_sync+0x19c/0x1a0 [ 285.472887] Code: f9400885 93407c23 937d7c27 11000421 (f86378a3) [ 285.473422] ---[ end trace 0000000000000000 ]--- It reproduced simply with below script: while [ 1 ] do /exportfs -r done & while [ 1 ] do insmod /nfsd.ko mount -t nfsd none /proc/fs/nfsd umount /proc/fs/nfsd rmmod nfsd done & So exporting interfaces to user space shall be done at last and cleanup at first place. With change there is no Kernel OOPs. Co-developed-by: Shubham Rana Signed-off-by: Shubham Rana Signed-off-by: Maninder Singh Reviewed-by: Jeff Layton Cc: stable@vger.kernel.org Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman