| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/ucma: Lock the handler in ucma_write_cm_event()
ctx->file may only be changed under the handler lock and the xa_lock, which
is what stops uevents being queued for a ctx while ucma_migrate_id() moves
it to another file. The CM core takes that lock before invoking
ucma_event_handler(), but the write() paths that queue uevents themselves
do not.
ucma_write_cm_event() re-reads ctx->file for each of its four dereferences,
so ucma_migrate_id() can swap it mid-sequence:
mutex_lock(&ctx->file->mut); /* file A */
list_add_tail(&uevent->list, &ctx->file->event_list); /* file B */
mutex_unlock(&ctx->file->mut); /* file B */
wake_up_interruptible(&ctx->file->poll_wait); /* file B */
The window is the mutex_lock() itself: the writer sleeps in it while the
migration reassigns ctx->file. The list_add_tail() then runs on file B's
event_list holding only file A's mutex:
list_add corruption. prev->next should be next (ffff888101320f30),
but was ffff88814a08c418. (prev=ffff88814a075c18).
kernel BUG at lib/list_debug.c:32!
Call Trace:
ucma_write_cm_event+0x36e/0x5e0
and file A's mut is left held forever, wedging its next writer in D state.
The uevent is also stranded on a list ucma_cleanup_ctx_events() will not
walk, so it outlives its context. /dev/infiniband/rdma_cm is 0666 and no
RDMA device is involved, so an unprivileged user reaches all of this.
Take the handler lock, as ucma_cleanup_mc_events() does; ctx->cm_id is
pinned by the ucma_get_ctx() reference. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/uverbs: Add UVERBS_ATTR_UHW to UVERBS_METHOD_REG_MR
The original commit missed that three drivers (mthca, irdma, siw) have UHW
data associated with reg_mr that cannot be passed through the ioctl. They
also assume that the udata cannot be NULL, so failing to pass a valid
udata can trigger a NULL udata crash in those drivers.
This never happens in real systems since in rdma-core ibv_cmd_reg_mr_ex()
does not accept a udata and those three drivers don't use it, however a
malicious userspace could trigger it. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/uverbs: Guard legacy bundles without method_elm
The legacy write() path dispatches through a uverbs_api_write_method, but
the uverbs_attr_bundle passed to provider code does not have an ioctl
method element. If malformed provider input causes the common uverbs
validation code to emit an error message, uverbs_get_handler_fn()
dereferences the uninitialized method_elm pointer.
Initialize method_elm explicitly for legacy bundles and make
uverbs_get_handler_fn() return NULL when no ioctl method is present. The
legacy dispatcher continues to use its local write method, while the ioctl
path continues to use the registered ioctl handler. |
| In the Linux kernel, the following vulnerability has been resolved:
regulator: as3722_get_regulator_dt_data: fix premature of_node_put leaving dangling of_node pointer
In as3722_get_regulator_dt_data(), of_get_child_by_name() acquires a
reference on np, which is then assigned to pdev->dev.of_node. The
function immediately calls of_node_put(np), releasing the reference and
leaving pdev->dev.of_node as a dangling pointer.
Remove the of_node_put(np) call to let the device hold the reference. |
| In the Linux kernel, the following vulnerability has been resolved:
ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page()
ring_buffer_alloc_read_page() is racy with ring_buffer_subbuf_order_set,
it can allocate a reader page with an outdated order. This isn't a big
issue, the user can still re-allocate a new reader page and try again.
However, what is more problematic is if the value of subbuf_order
changes in the middle of ring_buffer_alloc_read_page(). In that case,
bpage->order might not match the actual allocated memory.
Use bpage->order for the allocation to prevent this race. |
| In the Linux kernel, the following vulnerability has been resolved:
ring-buffer: Free cpu_buffer::free_page with subbuf_order
When sub-buffers use an order greater than 0, cpu_buffer->free_page is
allocated with subbuf_order. Use the correct order for
cpu_buffer->free_page. |
| In the Linux kernel, the following vulnerability has been resolved:
ring-buffer: Hold cpu_buffer::lock when resizing a subbuf
Because, ring_buffer_subbuf_order_set() can clear cpu_buffer->free_page,
hold cpu_buffer->lock to prevent races with
ring_buffer_alloc_read_page() and ring_buffer_free_read_page(). |
| In the Linux kernel, the following vulnerability has been resolved:
ring-buffer: Make cpu_buffer::free_page a buffer_data_read_page
Discarding a cached reader page after a concurrent ring buffer resize
uses the new global subbuf_order for the free_pages() call. This
mismatched order may crashes the kernel or leaks memory because the cached
page was allocated under the old size.
Save the actual free_page order alongside the page address to ensure we
always refer to the correct value and do not rely on the potentially
stalled cpu_buffer->subbuf_order value. The simplest is to make
free_page a buffer_data_read_page which already covers exactly what we
need: a page address and a page order. |
| In the Linux kernel, the following vulnerability has been resolved:
orangefs: fix double-free of trailer_buf on readdir copy failure
On a readdir downcall, orangefs_devreq_write_iter() frees
op->downcall.trailer_buf with vfree() when copy_from_iter_full() fails,
but does not clear the pointer before goto Efault. The waiter in
do_readdir() is then woken with a negative status and frees the same
pointer again on its r < 0 path, causing a deterministic double-free.
A client holding /dev/pvfs2-req triggers it by sending a readdir
downcall whose declared trailer_size exceeds the bytes it supplies.
Clear the pointer after freeing so the readdir-side vfree() becomes a
no-op. |
| In the Linux kernel, the following vulnerability has been resolved:
orangefs: skip leading spaces before parsing client debug masks
orangefs_prepare_cdm_array() sizes each client debug keyword buffer
with strcspn(cds_head, " "), but then parses the keyword with %s. The
%s conversion skips leading whitespace, while strcspn() does not.
If a client debug entry starts with a space, the allocation can be sized
for an empty keyword while sscanf() copies the following non-empty token.
This can write past the end of the allocated keyword buffer.
Skip leading spaces before computing the keyword length so the allocation
matches the string parsed by sscanf(). |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: always run deallocs on copy-on-write completion
Local fuzzing of 6.12.94 has found the following memory leak
caused by doing 'copy_file_range()' within the same filesystem:
unreferenced object 0xffff88812192c980 (size 32):
comm "syz.0.49", pid 12095, jiffies 4294964143
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 08 00 00 00 00 00 00 00 ................
c0 c5 92 21 81 88 ff ff 00 02 00 00 00 06 00 00 ...!............
backtrace (crc 7068d63f):
kmemleak_alloc_recursive include/linux/kmemleak.h:42 [inline]
slab_post_alloc_hook mm/slub.c:4152 [inline]
slab_alloc_node mm/slub.c:4197 [inline]
__kmalloc_cache_noprof+0x168/0x2c0 mm/slub.c:4358
kmalloc_noprof include/linux/slab.h:878 [inline]
ocfs2_find_per_slot_free_list fs/ocfs2/alloc.c:6618 [inline]
ocfs2_cache_block_dealloc+0x155/0x4b0 fs/ocfs2/alloc.c:6786
ocfs2_cache_extent_block_free fs/ocfs2/alloc.c:6819 [inline]
ocfs2_unlink_path+0x286/0x450 fs/ocfs2/alloc.c:2613
ocfs2_rotate_subtree_left fs/ocfs2/alloc.c:2779 [inline]
__ocfs2_rotate_tree_left+0x1f6f/0x2da0 fs/ocfs2/alloc.c:2985
ocfs2_rotate_tree_left+0x283/0xe00 fs/ocfs2/alloc.c:3237
ocfs2_try_to_merge_extent+0xf56/0x1a20 fs/ocfs2/alloc.c:3825
ocfs2_split_extent+0x15f4/0x2940 fs/ocfs2/alloc.c:5138
ocfs2_clear_ext_refcount+0x2f6/0x550 fs/ocfs2/refcounttree.c:3098
ocfs2_replace_clusters fs/ocfs2/refcounttree.c:3131 [inline]
ocfs2_make_clusters_writable fs/ocfs2/refcounttree.c:3255 [inline]
ocfs2_replace_cow+0x991/0x1660 fs/ocfs2/refcounttree.c:3349
ocfs2_refcount_cow_hunk fs/ocfs2/refcounttree.c:3427 [inline]
ocfs2_refcount_cow+0x5e1/0x9f0 fs/ocfs2/refcounttree.c:3470
ocfs2_prepare_inode_for_write fs/ocfs2/file.c:2340 [inline]
ocfs2_file_write_iter+0xbda/0x1880 fs/ocfs2/file.c:2451
iter_file_splice_write+0x890/0xf60 fs/splice.c:743
do_splice_from fs/splice.c:944 [inline]
direct_splice_actor+0x232/0x480 fs/splice.c:1167
splice_direct_to_actor+0x4b4/0xb60 fs/splice.c:1111
do_splice_direct_actor fs/splice.c:1210 [inline]
do_splice_direct+0x10f/0x1c0 fs/splice.c:1236
do_sendfile+0x430/0xbf0 fs/read_write.c:1388
unreferenced object 0xffff88812192c5c0 (size 32):
comm "syz.0.49", pid 12095, jiffies 4294964143
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
29 70 00 00 00 00 00 00 19 00 00 00 00 00 00 00 )p..............
backtrace (crc afec850f):
kmemleak_alloc_recursive include/linux/kmemleak.h:42 [inline]
slab_post_alloc_hook mm/slub.c:4152 [inline]
slab_alloc_node mm/slub.c:4197 [inline]
__kmalloc_cache_noprof+0x168/0x2c0 mm/slub.c:4358
kmalloc_noprof include/linux/slab.h:878 [inline]
kzalloc_noprof include/linux/slab.h:1014 [inline]
ocfs2_cache_block_dealloc+0x25c/0x4b0 fs/ocfs2/alloc.c:6793
ocfs2_cache_extent_block_free fs/ocfs2/alloc.c:6819 [inline]
ocfs2_unlink_path+0x286/0x450 fs/ocfs2/alloc.c:2613
ocfs2_rotate_subtree_left fs/ocfs2/alloc.c:2779 [inline]
__ocfs2_rotate_tree_left+0x1f6f/0x2da0 fs/ocfs2/alloc.c:2985
ocfs2_rotate_tree_left+0x283/0xe00 fs/ocfs2/alloc.c:3237
ocfs2_try_to_merge_extent+0xf56/0x1a20 fs/ocfs2/alloc.c:3825
ocfs2_split_extent+0x15f4/0x2940 fs/ocfs2/alloc.c:5138
ocfs2_clear_ext_refcount+0x2f6/0x550 fs/ocfs2/refcounttree.c:3098
ocfs2_replace_clusters fs/ocfs2/refcounttree.c:3131 [inline]
ocfs2_make_clusters_writable fs/ocfs2/refcounttree.c:3255 [inline]
ocfs2_replace_cow+0x991/0x1660 fs/ocfs2/refcounttree.c:3349
ocfs2_refcount_cow_hunk fs/ocfs2/refcounttree.c:3427 [inline]
ocfs2_refcount_cow+0x5e1/0x9f0 fs/ocfs2/refcounttree.c:3470
ocfs2_prepare_inode_for_write fs/ocfs2/file.c:2340 [inline]
ocfs2_file_write_iter+0xbda/0x1880 fs/ocfs2/file.c:2451
iter_file_splice_write+0x890/0xf60 fs/splice.c:743
do_splice_from fs/splice.c:9
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: bound namelen in dlm_migrate_request_handler
Patch series "ocfs2/dlm: bound peer-controlled lengths in the o2dlm".
The o2dlm receive handlers trust u8 length and count fields from the wire
without bounding them, so a node in a DLM domain can corrupt or panic any
other node with a malformed message. Three defects:
- dlm_migrate_request_handler() passes migrate->namelen unchecked to
dlm_init_mle(), which memcpy()s it into the 32-byte mname[] of an
o2dlm_mle slab object: a heap out-of-bounds write of up to ~215
attacker-controlled bytes.
- dlm_mig_lockres_handler() passes mres->lockname_len unchecked to
dlm_init_lockres(), which memcpy()s it into the 32-byte o2dlm_lockname
slab object: a heap out-of-bounds write of up to ~223 bytes.
- the same handler trusts mres->num_locks without checking that the
message is large enough to hold that many entries, so
dlm_process_recovery_data() walks mres->ml[] past the kmalloc(data_len)
copy and trips a BUG_ON (an out-of-bounds read ending in a panic).
The other o2dlm receive handlers already reject an oversized name; the
migration and recovery handlers have omitted it since the DLM was added
(see the Fixes tags). Patch 1 bounds namelen; patch 2 validates
lockname_len, num_locks, and the payload size. Conforming recovery and
migration traffic is unaffected.
o2net authenticates peers only by the DLM domain key, so any node that has
joined the domain -- including a compromised or malicious member -- can
send these messages. There is no local trigger; the attacker must already
be a member of the cluster.
Each sink was confirmed under KASAN with an out-of-tree module mirroring
it exactly -- a kmem_cache/kmalloc of the real destination size, then the
same unclamped memcpy/loop: slab-out-of-bounds Write for the two writes,
Read for the recovery walk, and a panic. A userspace AddressSanitizer
build faults identically under -m32 and -m64. Scrubbed logs are available
on request.
I reported this privately to security@kernel.org and the ocfs2 maintainers
on 2026-06-20; with no response after the standard embargo period I am
posting the fix publicly. I have no embargo requirement.
This patch (of 2):
A node receiving a DLM_MIGRATE_REQUEST message trusts the peer-supplied
name length (migrate->namelen) without bounding it. dlm_init_mle() then
copies that many bytes into the fixed DLM_LOCKID_NAME_MAX-byte mname[]
array of an o2dlm_mle slab object, so a malformed message from a cluster
peer overflows the slab object by up to ~215 bytes: a heap out-of-bounds
write of attacker-controlled data, reachable by any node in the domain.
Reject an oversized name, the way dlm_master_request_handler() and the
other o2dlm receive handlers already do; the migration handler omits the
check entirely. Conforming messages are unaffected. |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate lengths in dlm_mig_lockres_handler
A node receiving a DLM_MIG_LOCKRES message trusts several fields of the
peer-supplied dlm_migratable_lockres without validation. num_locks and
lockname_len are bounded only on the sending side, and the message is
never checked to actually carry num_locks migratable_lock entries. As a
result dlm_process_recovery_data() walks mres->ml[0..num_locks) past the
kmalloc(data_len) copy of the message (an out-of-bounds read that ends in
a BUG_ON panic), and dlm_init_lockres() copies lockname_len bytes into the
fixed 32-byte o2dlm_lockname slab object (a heap out-of-bounds write).
Both are reachable by any node in the domain.
Validate these fields right after dlm_grab(), before anything uses them --
including the not-joined error path, which already prints mres->lockname
with the unbounded lockname_len as a %.*s precision. Reject the message
unless lockname_len <= DLM_LOCKID_NAME_MAX, num_locks <=
DLM_MAX_MIGRATABLE_LOCKS (the bound the sender already asserts), and the
payload is large enough to hold the claimed locks. Conforming recovery
and migration messages are unaffected. |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate rl_used against rl_count in refcount block validator
ocfs2_find_refcount_rec_in_rl() walks the on-disk refcount record array
with:
for (; i < le16_to_cpu(rb->rf_records.rl_used); i++) {
rec = &rb->rf_records.rl_recs[i];
...
rl_recs[] lives in a single metadata block (4096 bytes on the common
configuration), so its real capacity is fixed by
ocfs2_refcount_recs_per_rb(sb) (247 records for a 4K block with the
16-byte ocfs2_refcount_rec). rl_used and rl_count are both read directly
off disk by ocfs2_validate_refcount_block() and are never checked against
that capacity, nor against each other, before any refcount/reflink/CoW
operation walks the array.
A crafted (or corrupted) refcount block with rl_used == 0xffff makes the
loop above walk far past the end of the block, dereferencing rl_recs[i]
for i up to 65534. The resulting index is then handed to the sibling
ocfs2_insert_refcount_rec(), whose insert-shift does:
if (index < le16_to_cpu(rf_list->rl_used))
memmove(&rf_list->rl_recs[index + 1],
&rf_list->rl_recs[index],
(le16_to_cpu(rf_list->rl_used) - index) *
sizeof(struct ocfs2_refcount_rec));
i.e. a memmove() of up to (0xffff - index) * 16 bytes (~1 MiB) from an
offset already past the block. This is reachable from an ordinary reflink
(FICLONE) against a crafted/corrupted ocfs2 image: attaching an extent
whose cpos sorts past every real record in the leaf forces the lookup to
run off the end instead of returning early on a match. The attacker model
is local: CAP_SYS_ADMIN mounting a crafted or corrupted ocfs2 image, or a
raw write to the block device backing an already-mounted ocfs2 filesystem.
ocfs2_validate_refcount_block() already validates the block's ECC,
signature, rf_blkno and rf_fs_generation, but never rl_count/rl_used
against the block's actual on-disk capacity. This is the same class of
gap that ocfs2_validate_extent_block() (fs/ocfs2/alloc.c) already closes
for the sibling extent-list header, which checks both the record capacity
and the "used" bound before any code walks h_list.l_recs[]:
if (le16_to_cpu(eb->h_list.l_count) != ocfs2_extent_recs_per_eb(sb)) {
rc = ocfs2_error(...);
goto bail;
}
if (le16_to_cpu(eb->h_list.l_next_free_rec) >
le16_to_cpu(eb->h_list.l_count)) {
rc = ocfs2_error(...);
goto bail;
}
Add the equivalent pair of checks to ocfs2_validate_refcount_block():
reject a refcount block whose rl_count does not match the fixed per-block
capacity returned by ocfs2_refcount_recs_per_rb(), and reject rl_used >
rl_count. Both checks are skipped when OCFS2_REFCOUNT_TREE_FL is set,
because in that case the same union bytes hold an ocfs2_extent_list
(rf_list), not the refcount record list (rf_records) -- that layout is
already validated separately by ocfs2_validate_extent_block() when the
referenced extent block is read. This mirrors the existing
"!(rb->rf_flags & OCFS2_REFCOUNT_TREE_FL)" guard used elsewhere in this
file (e.g. ocfs2_get_refcount_rec()) to decide whether rf_records or
rf_list is the live member of the union.
With this in place, a forged rl_used/rl_count is caught at block
validation time (ocfs2_error()), consistent with every other corruption
check in this function, instead of driving an out-of-bounds read in
ocfs2_find_refcount_rec_in_rl() and a subsequent out-of-bounds memmove()
in ocfs2_insert_refcount_rec().
Verified against a crafted image on a v6.19 KASAN (KASAN_GENERIC) build:
replaying the same reflink (FICLONE) reliably hit a KASAN report in
__ocfs2_increase_refcount()/ocfs2_insert_refcount_rec() before this patch,
and triggers no report once ocfs2_validate_refcount_block() rejects the
forged rl_used/rl_count. |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate directory-index entry counts when reading metadata
ocfs2_validate_dx_leaf() and ocfs2_validate_dx_root() check the ECC and
signature of an indexed-directory block before it reaches higher-level
callers, but neither validator bounds the ocfs2_dx_entry_list counts
against the capacity of the block that holds them.
ocfs2_dx_dir_search() then walks
for (i = 0; i < le16_to_cpu(entry_list->de_num_used); i++)
dx_entry = &entry_list->de_entries[i];
over de_num_used entries with no bounds check. entry_list is either
dx_leaf->dl_list (from ocfs2_read_dx_leaf) or, for an inline root,
dx_root->dr_entries. A crafted on-disk image can set de_num_used (and
de_count, which is the __counted_by_le() bound of de_entries) to 0xffff
and make the walk read far past the end of the 4KB metadata block, giving
a slab out-of-bounds read reachable from any path lookup, stat() or open()
on an indexed directory once the image is mounted.
Commit 775c17386a6f ("ocfs2: validate dx_root extent list fields during
block read") already bounds dr_list for the non-inline dx_root, but left
the inline dr_entries path and the dx_leaf dl_list unchecked. Add the
same read-time validation for both entry lists: de_count must equal the
capacity of the block (ocfs2_dx_entries_per_leaf()/per_root()) and
de_num_used must not exceed de_count, rejecting corrupted metadata with
-EFSCORRUPTED before ocfs2_dx_dir_search() can walk an out-of-range entry
array.
de_count is always written as exactly the block capacity when a leaf or
inline root is formatted, so the equality check does not reject any valid
image.
Found by 0sec automated security-research tooling (https://0sec.ai). |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix readdir position truncation on 32-bit kernels
In ocfs2_dir_foreach_blk_el(), the directory cookie position is
rebuilt with
ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1)) | offset;
`ctx->pos` is loff_t (signed 64-bit), while `sb->s_blocksize` is
unsigned long. On 32-bit kernels unsigned long is 32-bit, so the mask
~(sb->s_blocksize - 1)
is computed as a 32-bit unsigned value (e.g. 0xfffff000 for a 4 KiB
block size). In the AND expression with the 64-bit `ctx->pos`, that
unsigned operand is zero-extended to 64 bits per the usual arithmetic
conversions, yielding 0x00000000fffff000. The high 32 bits of
`ctx->pos` are silently cleared, even though directory size is
allowed to exceed 4 GiB.
When readdir() crosses the 4 GiB boundary on a 32-bit kernel the
position is reset back into the first 4 GiB block, making the
re-validation path re-enumerate already-returned dirents indefinitely.
This is ocfs2_dir_foreach_blk_el(), the extent-list readdir path taken
for all non-inline directories, so a directory large enough to cross
4 GiB reaches it.
This is the same class of bug that commit 3dce5bb82c97 ("exfat: Fix
bitwise operation having different size") fixed in exfat, and the
fix mirrors the equivalent ext4 fix in this series. Cast the operand
to loff_t so the mask is 64-bit before the AND:
ctx->pos = (ctx->pos & ~((loff_t)sb->s_blocksize - 1)) | offset;
64-bit kernels are unaffected. |
| In the Linux kernel, the following vulnerability has been resolved:
openrisc: fix arbitrary kernel memory access via or1k_atomic syscall
sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user
pointers, v1 and v2, and swaps the words they point to in hand-written
assembly.
l.lwz r29,0(r4)
l.lwz r27,0(r5)
l.sw 0(r4),r27
l.sw 0(r5),r29
The pointers are not checked with access_ok(). The four memory
accesses also have no exception table entries.
A caller passes a kernel address as either pointer, and the syscall
reads from and writes to it directly.
This gives an unprivileged process a kernel read/write primitive. It
overwrites kernel data such as the sys_call_table, gaining code
execution in kernel context.
Check both pointers before entering the critical section. Add fixups
for the four memory accesses so faults on valid but unmapped user
addresses return -EFAULT.
[shorne@gmail.com: fix comment style] |
| In the Linux kernel, the following vulnerability has been resolved:
ipmi: Fix use-after-free of cmd_rcvr in _ipmi_destroy_user()
Commit 9e91f8a6c868 ("ipmi:msghandler: Remove srcu for the
ipmi_interfaces list") dropped the synchronize_rcu() between unlinking
the command receivers from intf->cmd_rcvrs and freeing them, updating
only the comment that explains why the barrier is needed.
The cmd_rcvrs list is still traversed under plain RCU: find_cmd_rcvr()
walks it inside rcu_read_lock(), and handle_ipmb_get_msg_cmd() borrows
rcvr->user from that lookup within the same read-side section. Without
the grace period, _ipmi_destroy_user() can kfree() a cmd_rcvr while a
reader still holds a pointer to it, causing a use-after-free.
The rework only made srcu unnecessary for the interfaces list; the
cmd_rcvrs list still relies on plain RCU. Restore the synchronize_rcu()
before freeing the receivers. |
| In the Linux kernel, the following vulnerability has been resolved:
lockd: pin next file across nlm_inspect_file lock-drop
nlm_traverse_files() pins the current file with f_count++ across
a mutex_unlock for nlm_inspect_file(), but nothing pins the saved
next pointer. A concurrent nlm_release_file() can kfree the next
file during the unlock window, and the iterator dereferences freed
memory on the next loop step.
Pin both current and next before the lock-drop. Advance by
swapping the pinned cursors at the end of each iteration so next
is always held alive across the unlock.
Always call nlm_file_release() after dropping the iteration pin,
regardless of whether the file matched the predicate. Use
nlm_file_inuse(), which does a live walk of the inode lock list,
rather than the cached f_locks field, so skipped files that never
ran nlm_inspect_file() are evaluated correctly.
Because every file in a hash bucket is now pinned and released,
files skipped by the is_failover_file predicate that have no
locks, blocks, shares, or external references are deleted during
traversal. The old code never evaluated skipped files for
cleanup. The new behavior is intentional: such files are stale
and should not persist in the table. |
| In the Linux kernel, the following vulnerability has been resolved:
lockd: fix NULL dereference on lockowner allocation failure
nlmclnt_locks_init_private() installs NLM file lock operations even when
nlmclnt_find_lockowner() fails to allocate a lockowner. nlmclnt_proc()
then returns -ENOMEM, but the VFS still tears down the partially
initialized file_lock and calls locks_release_private().
That invokes nlmclnt_locks_release_private(), which dereferences
fl->fl_u.nfs_fl.owner and crashes because the owner was never installed.
Clear fl_ops before attempting to initialize the NLM private state, and
install the NLM lock operations only after a lockowner has been allocated
successfully. |
