NFSv4.1: fix layout segment leak on the pnfs_layout_process() forget path
In the Linux kernel, the following vulnerability has been resolved:
NFSv4.1: fix layout segment leak on the pnfs_layout_process() forget path
When the server returns a new layout stateid while a valid one is still
held, pnfs_layout_process() calls pnfs_mark_matching_lsegs_return() on
the on-stack free_me list and jumps to out_forget. Segments whose
reference count drops to zero are unlinked from lo->plh_segs and moved
to free_me by mark_lseg_invalid(); for an idle cached segment the layout
header holds the only reference, so this happens on the first decrement.
out_forget never drains free_me -- only the success path calls
pnfs_free_lseg_l
In the Linux kernel, the following vulnerability has been resolved:
lockd, nfsd: RCU-protect nlmsvc_ops dispatch
nlmsvc_ops is published by nfsd_lockd_init() and cleared by
nfsd_lockd_shutdown() with plain stores, while lockd dereferences
it unguarded from dispatch sites in fs/lockd/svcsubs.c. The pointer
targets nfsd's .rodata and the fopen/fclose callbacks live in nfsd's
.text, so a stale load after rmmod nfsd results in either a NULL
deref or a module-text use-after-free.
Declare nlmsvc_ops as __rcu, publish via rcu_assign_pointer(), clear
via RCU_INIT_POINTER() + synchronize_rcu(). Add a struct module
*owner field to nlmsvc_binding and
nfsd: RCU-protect cl_cb_session to fix use-after-free on session teardown
In the Linux kernel, the following vulnerability has been resolved:
nfsd: RCU-protect cl_cb_session to fix use-after-free on session teardown
After a DESTROY_SESSION the per-session teardown path can free a
session while rpciod still holds an inflight callback rpc_task that
dereferences clp->cl_cb_session. nfsd4_probe_callback_sync() flushes
cl_callback_wq, but once nfsd4_run_cb_work() has called
rpc_call_async() the rpc_task lives on rpciod; flushing the workqueue
does not wait for it. rpc_shutdown_client() does drain rpciod tasks,
but uses a 1-second wait_event_timeout — tasks stuck in rpc_delay()
(e.g. 2-second NFS4ERR_DELAY retries) c
In the Linux kernel, the following vulnerability has been resolved:
nfsd: release path refs on follow_down() error
nfsd_cross_mnt() initializes a local struct path with mntget() and
dget() before calling follow_down(). On a negative return the error
arm jumps to out without releasing those references:
err = follow_down(&path, follow_flags);
if (err < 0)
goto out;
follow_down() never drops the caller's entry-time refs on any error
sub-case; for example a pre-cross d_manage() failure leaves path
untouched, so the mntget()/dget() taken on entry survive the call.
Every other early-exit arm in nfsd_cross_mnt() (other-names
nfsd: Reset write verifier when async COPY writeback fails
In the Linux kernel, the following vulnerability has been resolved:
nfsd: Reset write verifier when async COPY writeback fails
Async COPY captures nn->writeverf at request time and reports it to
the client via CB_OFFLOAD after the worker kthread completes. When
the post-copy vfs_fsync_range() or filemap_check_wb_err() in
_nfsd_copy_file_range() reports an error, the worker correctly
leaves NFSD4_COPY_F_COMMITTED clear so that CB_OFFLOAD encodes
wr_stable_how as NFS_UNSTABLE, but the server's write verifier is
not rotated.
A client that receives NFS_UNSTABLE in CB_OFFLOAD follows up with
COMMIT to make the copied data durable. With the veri
nfsd: restore rq_status_counter to even on all nfsd_dispatch() exit paths
In the Linux kernel, the following vulnerability has been resolved:
nfsd: restore rq_status_counter to even on all nfsd_dispatch() exit paths
nfsd_dispatch() sets rq_status_counter to an odd value once a request has
been decoded, and back to an even value once it has been fully processed,
forming a seq-lock like protocol with the lockless reader in
nfsd_nl_rpc_status_get_dumpit().
Only the fully successful path restored the counter to even. The cache-hit
(RC_REPLY), drop (RC_DROPIT / RQ_DROPME) and encode-error paths all return
after the odd-valued store without ever bringing the counter back to even.
Once one of those paths is taken, rq_s
nfsd: sample writeback error cursor before async COPY loop
In the Linux kernel, the following vulnerability has been resolved:
nfsd: sample writeback error cursor before async COPY loop
_nfsd_copy_file_range() samples dst->f_wb_err into "since"
after the copy loop, then uses it to detect writeback errors
via filemap_check_wb_err() once vfs_fsync_range() returns.
Because the nfsd_file cache reuses a single struct file
across requests targeting the same inode, a concurrent
COMMIT or stable WRITE on dst advances dst->f_wb_err to the
current mapping->wb_err via file_check_and_advance_wb_err()
during its own vfs_fsync_range(). If that advancement lands
between the writeback error appearing in mapping->w
nfsd: set SC_STATUS_FREED in nfsd4_drop_revoked_stid for delegations
In the Linux kernel, the following vulnerability has been resolved:
nfsd: set SC_STATUS_FREED in nfsd4_drop_revoked_stid for delegations
nfsd4_drop_revoked_stid() handles FREE_STATEID for admin-revoked
delegations but does not set SC_STATUS_FREED before releasing cl_lock.
revoke_delegation() uses this flag to detect whether FREE_STATEID has
already processed the delegation -- without it, the freed delegation is
added to cl_revoked via list_add(), producing a use-after-free when
cl_revoked is later traversed in __destroy_client().
The SC_STATUS_REVOKED path in nfsd4_free_stateid() (line 7983) already
sets SC_STATUS_FREED correctly. Apply th
nfsd: size fh_verify server sockaddr slot by xpt_locallen
In the Linux kernel, the following vulnerability has been resolved:
nfsd: size fh_verify server sockaddr slot by xpt_locallen
The nfsd_fh_verify and nfsd_fh_verify_err tracepoints declare the
server sockaddr slot sized by xpt_remotelen but fill it from
xpt_local using xpt_locallen:
TP_STRUCT__entry(
...
__sockaddr(server, rqstp->rq_xprt->xpt_remotelen)
...
)
TP_fast_assign(
...
__assign_sockaddr(server, &rqstp->rq_xprt->xpt_local,
rqstp->rq_xprt->xpt_locallen);
...
)
When xpt_locallen exceeds xpt_remotelen, __assign_sockad
nfsd: validate nseconds in TIME_DELEG decode paths
In the Linux kernel, the following vulnerability has been resolved:
nfsd: validate nseconds in TIME_DELEG decode paths
The xdrgen-based TIME_DELEG_ACCESS and TIME_DELEG_MODIFY decode arms
store a raw uint32_t nseconds directly into tv_nsec without enforcing
nseconds < NSEC_PER_SEC. The legacy nfsd4_decode_nfstime4 has this
check but the TIME_DELEG paths do not. A malformed timespec can
propagate through notify_change() to disk.
Add range checks in both nfs4xdr.c (SETATTR path) and
nfs4callback.c (CB_GETATTR path).
nfsd: validate sockaddr length per family in listener_set
In the Linux kernel, the following vulnerability has been resolved:
nfsd: validate sockaddr length per family in listener_set
nfsd_sock_nl_policy declares NFSD_A_SOCK_ADDR as a bare NLA_BINARY
attribute with no minimum length. A CAP_NET_ADMIN caller can send a
16-byte NFSD_A_SOCK_ADDR with sa_family=AF_INET6, causing a 12-byte
OOB read across three consumers (rpc_cmp_addr_port, svc_find_listener,
kernel_bind).
nfsd_nl_listener_set_doit() also parsed and validated each listener
entry inline in two separate loops, interleaved with mutating the
running listener configuration. The validation was duplicated, used an
open-coded "nla_len < sizeof
nfsd: validate symlink target length in NFSv4 CREATE
In the Linux kernel, the following vulnerability has been resolved:
nfsd: validate symlink target length in NFSv4 CREATE
nfsd4_decode_create() accepts an unbounded cr_datalen from the wire for
NF4LNK symlink targets, allowing a client to force a kmalloc of up to
the maximum RPC payload size (several MiB) per COMPOUND op that persists
until compound teardown. The VFS rejects oversized targets with
ENAMETOOLONG, but the allocation has already occurred.
Reject cr_datalen == 0 early with nfserr_inval and cr_datalen greater
than NFS4_MAXPATHLEN (PATH_MAX) with nfserr_nametoolong to bound the
allocation.
nfsd: widen nfsd_genl_rqstp address fields to sockaddr_storage
In the Linux kernel, the following vulnerability has been resolved:
nfsd: widen nfsd_genl_rqstp address fields to sockaddr_storage
struct nfsd_genl_rqstp declares rq_daddr and rq_saddr as plain
"struct sockaddr" (16 bytes). When an IPv6 NFS client is connected,
nfsd_genl_rpc_status_compose_msg() casts these fields to
"struct sockaddr_in6 *" (28 bytes) and reads sin6_addr at offset 8..24,
which extends 8 bytes past the end of the 16-byte sockaddr field into
the adjacent rq_flags member. The 16-byte nla_put_in6_addr then ships 8
bytes of truncated IPv6 address followed by 8 bytes of rq_flags to
userspace via the NFSD_A_RPC_STATUS_SADDR6/DADDR
nfsd: add fh_want_write() for early-verified SETATTR in nfsd_proc_setattr()
In the Linux kernel, the following vulnerability has been resolved:
nfsd: add fh_want_write() for early-verified SETATTR in nfsd_proc_setattr()
The BOTH_TIME_SET branch calls fh_verify() early so setattr_prepare()
can inspect the dentry. This causes nfsd_setattr() to skip
fh_want_write(), so notify_change() runs without a mount write
reference.
Add the missing fh_want_write() call after the early fh_verify().
nfsd: block non-SAVEFH ops after FOREIGN PUTFH to prevent NULL deref
In the Linux kernel, the following vulnerability has been resolved:
nfsd: block non-SAVEFH ops after FOREIGN PUTFH to prevent NULL deref
When CONFIG_NFSD_V4_2_INTER_SSC is enabled, nfsd4_putfh() can return
success with fh_dentry and fh_export both NULL if fh_verify() returns
nfserr_stale and putfh->no_verify is true. The NFSD4_FH_FOREIGN flag
is set, but the compound dispatch loop only uses this flag to bypass
the nfserr_nofilehandle check -- it does not prevent subsequent ops
from running with a NULL fh_dentry.
A remote client can exploit this by crafting a COMPOUND that includes
an inter-SSC COPY (which causes check_if_stalefh_allowed()
nfsd: cap decoded POSIX ACL count to bound sort cost
In the Linux kernel, the following vulnerability has been resolved:
nfsd: cap decoded POSIX ACL count to bound sort cost
nfsd4_decode_posixacl() reads a u32 entry count off the wire and passes
it straight to posix_acl_alloc() and sort_pacl_range(). The latter is
an O(n^2) bubble sort, so a client-chosen count drives unbounded CPU in
the server's compound processing path.
nfsd4_decode_posixacl()
xdr_stream_decode_u32(&count) /* uncapped u32 */
posix_acl_alloc(count, GFP_KERNEL)
sort_pacl_range(*acl, 0, count - 1) /* O(n^2) bubble sort */
The encoder side in the same file already rejects ACLs whose a_count
exceed
nfsd: check client ownership when cancelling a copy-notify stateid
In the Linux kernel, the following vulnerability has been resolved:
nfsd: check client ownership when cancelling a copy-notify stateid
On the OFFLOAD_CANCEL path (clp != NULL), manage_cpntf_state() freed the
target cpntf state without checking ownership. The lookup key
st->si_opaque.so_id is allocated cyclically (guessable) and the embedded
clientid is the fixed per-net nn->s2s_cp_cl_id, so any authenticated
NFSv4.2 client could cancel and free another client's copy-notify
stateid.
Compare the creating clientid recorded in state->cp_p_clid against the
requesting client's cl_clientid and return nfserr_bad_stateid on a
mismatch instead of fr
Media · CVSS 5.3EPSS 0,18%Sin corrección publicada
nfsd: check nfsd4_acl_to_attr() return value in nfsd4_create()
In the Linux kernel, the following vulnerability has been resolved:
nfsd: check nfsd4_acl_to_attr() return value in nfsd4_create()
nfsd4_create() stores the return value of nfsd4_acl_to_attr() in
status, but the switch(create->cr_type) block unconditionally
overwrites it in every branch. ACL translation errors are silently
discarded, and the CREATE proceeds without the requested ACL.
Add an early exit check after nfsd4_acl_to_attr(), matching the
pattern already used in nfsd4_setattr().
[ cel: prefer NFS4ERR_BADTYPE over NFS4ERR_ATTRNOTSUPP ]
nfsd: clear CALLBACK_RUNNING on failed delegation recall queue
In the Linux kernel, the following vulnerability has been resolved:
nfsd: clear CALLBACK_RUNNING on failed delegation recall queue
nfsd_break_one_deleg() sets NFSD4_CALLBACK_RUNNING via test_and_set_bit
at entry to serialize recall work, then calls nfsd4_run_cb() to queue
the recall. When the queue attempt fails the refcount bump is undone,
but the RUNNING bit is left set. The only site that clears the bit is
nfsd41_destroy_cb() (fs/nfsd/nfs4callback.c), which runs from the
workqueue and is therefore unreachable when nothing was queued.
The bit becomes a permanent latch on dp->dl_recall.cb_flags: every
subsequent break_lease() on the sam
nfsd: clear opcnt on compound arg release to prevent OOB read
In the Linux kernel, the following vulnerability has been resolved:
nfsd: clear opcnt on compound arg release to prevent OOB read
nfsd4_release_compoundargs() resets args->ops to the inline iops[8]
array when the dynamically-allocated ops buffer is freed, but leaves
args->opcnt at its original value (which can be up to 200 for NFSv4.1+
compounds).
If rq_status_counter is stuck at an odd value (which can happen when
nfsd_dispatch() hits an error path after setting it odd), the RPC
status dumpit handler reads min(opcnt, 16) entries from args->ops[].
Since iops only has 8 elements and is the last field in struct
nfsd4_compoundargs, reading in