| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| This CVE ID has been rejected or withdrawn by its CVE Numbering Authority. |
| In the Linux kernel, the following vulnerability has been resolved:
xprtrdma: Decouple req recycling from RPC completion
rl_kref formerly served two distinct lifetimes through a single
refcount: it gated when a Reply could wake its RPC task, and it
gated when an rpcrdma_req could return to its free pool. The
marshal path took the Send-side reference only when SGEs needed
DMA-unmap (sc_unmap_count > 0), which made a Send carrying only
pre-registered buffers an exception: the Reply handler dropped
rl_kref from 1 to 0 and freed the req while the HCA might still
be DMA-reading from its send buffer.
Give rl_kref a narrower job. The RPC layer takes one reference
when slot allocation hands a req out. rpcrdma_prepare_send_sges()
takes a Send-side reference unconditionally after WR preparation
succeeds. xprt_rdma_free_slot() and xprt_rdma_bc_free_rqst() drop
the RPC-layer reference; rpcrdma_sendctx_unmap() drops the
Send-side reference. The req returns to its free pool only after
both owners have signed off.
The existing kref_init(&req->rl_kref) call in
rpcrdma_prepare_send_sges() is removed. Initialization moves to
the slot-allocation paths (xprt_rdma_alloc_slot and
rpcrdma_bc_rqst_get), and the release callback re-arms rl_kref
before the req returns to a free pool. A re-init in the marshal
path would discard the RPC-layer reference that already exists
on entry.
Three invariants follow:
- Any rpcrdma_req held by an rpc_rqst has rl_kref >= 1.
xprt_rdma_alloc_slot(), rpcrdma_bc_rqst_get(), and the
backlog-wake branch in xprt_rdma_alloc_slot() each kref_init
rl_kref before publishing the req. Without this invariant,
an RPC task that aborts between slot allocation and marshal
(gss_refresh failure or signal during call_connect, for
example) would drive xprt_release() ->
xprt_rdma_free_slot() -> kref_put against a refcount of
zero, saturating refcount_t and stranding the slot.
- The Send-side reference is taken only after WR prep
succeeds. A mapping failure in rpcrdma_prepare_send_sges()
runs rpcrdma_sendctx_cancel(), which DMA-unmaps the sendctx
and clears sc_req without touching rl_kref. The sendctx
ring walks in rpcrdma_sendctx_put_locked() and
rpcrdma_sendctxs_destroy() skip entries with sc_req == NULL,
so a burst of -EIO marshal failures cannot hold reqs off
rb_send_bufs.
- The release callback re-arms rl_kref so the next consumer
enters with the invariant satisfied.
Replies now complete the RPC directly. rpcrdma_reply_handler()
calls rpcrdma_complete_rqst() in place of kref_put on the
non-LocalInv branch. The LocalInv branch already completes the
RPC from frwr_unmap_async() and is unaffected.
Because Send-side references can now outlive RPC completion,
connection teardown drains sendctx entries whose unsignaled
Sends never had a later signaled completion to walk the ring.
rpcrdma_sendctxs_destroy() walks the active range and runs
rpcrdma_sendctx_unmap() on each entry with a non-NULL sc_req
before the request buffers are reset, and is moved ahead of
rpcrdma_reqs_reset() in rpcrdma_xprt_disconnect() so the reqs
are still in their pre-reset state when the Send-side refs are
released.
The drain creates a teardown-ordering hazard on the backchannel
path. With the new lifetime, releasing a bc_prealloc req from
rpcrdma_req_release() re-adds it to bc_pa_list. The disconnect
in xprt_rdma_destroy() runs after xprt_destroy_backchannel() has
already emptied bc_pa_list, so the drained reqs would otherwise
leak. xprt_rdma_destroy() now runs xprt_rdma_bc_destroy(xprt, 0)
a second time after the disconnect to reclaim them. |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: Fix possible use after free
In dma_release_channel(), check chan->device->privatecnt after call
dma_chan_put(). However, dma_chan_put() call dma_device_put() which could
release the last reference of the device if the DMA provider is already
gone and hence free it.
Fixes it by moving dma_chan_put() after the check. |
| In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: call _ntfs_bad_inode() when failing to rename
It is safe to call _ntfs_bad_inode on live inodes since:
commit 519b078998ce ("fs/ntfs3: Exclude call make_bad_inode for live nodes.")
The WARN_ON was added when it wasn't safe by:
commit d99208b91933 ("fs/ntfs3: cancle set bad inode after removing name fails")
Replace the WARN_ON with a call to _ntfs_bad_inode() to prevent further
operations on the inconsistent inode. |
| In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: add bounds check to run_get_highest_vcn()
run_get_highest_vcn() parses a packed NTFS mapping-pairs buffer without
any length bound, relying solely on a 0x00 terminator to stop. A
crafted $LogFile UpdateMappingPairs record whose embedded attribute
contains mapping-pairs runs without a terminator causes the function to
read past the slab allocation, triggering a KASAN slab-out-of-bounds
read on mount.
The sibling function run_unpack() received an analogous bounds-check in
commit b62567bca474 ("ntfs3: add buffer boundary checks to run_unpack()"),
but run_get_highest_vcn() was missed.
Take a run_buf_size parameter and reject any run header whose payload
would extend past the buffer end, mirroring the pattern used by
run_unpack(). The caller in fslog.c passes the remaining attribute
bytes after the mapping-pairs offset.
KASAN report (on mainline v7.1 merge window HEAD):
BUG: KASAN: slab-out-of-bounds in run_get_highest_vcn+0x3c0/0x410
Read of size 1 at addr ffff88800e2d5400 by task mount/72
Call Trace:
run_get_highest_vcn+0x3c0/0x410
do_action.isra.0+0x3ba8/0x7b50
log_replay+0x9ddd/0x10200
ntfs_loadlog_and_replay+0x4ad/0x610
ntfs_fill_super+0x214a/0x4540 |
| In the Linux kernel, the following vulnerability has been resolved:
iio: accel: mma8452: handle I2C read error(s) in mma8452_read()
Currently, If i2c_smbus_read_i2c_block_data() fails but
mma8452_set_runtime_pm_state() succeeds, mma8452_read() returns 0.
As a result, the caller mma8452_read_raw() assumes the read was
successful and proceeds to use a buffer containing uninitialized
stack memory.
Add proper checking of the I2C read return value and propagate errors
to the caller. |
| In the Linux kernel, the following vulnerability has been resolved:
iio: adc: xilinx-ams: fix out-of-bounds channel lookup in event handling
ams_event_to_channel() may return a pointer past the end of
dev->channels when no matching scan_index is found. This can lead
to invalid memory access in ams_handle_event().
Add a bounds check in ams_event_to_channel() and return NULL when
no channel is found. Also guard the caller to safely handle this
case. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_core: Fix UAF in hci_unregister_dev()
hci_unregister_dev() does not disable cmd_timer and ncmd_timer
before the hci_dev structure is freed. If a timeout fires
during device teardown, the callback dereferences freed memory
(including the hdev->reset function pointer), leading to a
use-after-free.
Add disable_delayed_work_sync() calls alongside the existing
disable_work_sync() calls to ensure both timers are fully
quiesced before teardown proceeds. |
| In the Linux kernel, the following vulnerability has been resolved:
vfio/qat: fix f_pos race in qat_vf_resume_write()
qat_vf_resume_write() checks filp->f_pos before taking migf->lock, but
copies into the migration-state buffer after taking the lock and
re-reading the shared file position.
Two concurrent writers could therefore pass the bounds check with the
old offset, then have the second writer copy after the first advanced
f_pos, writing past the end of the migration-state buffer.
Take migf->lock before doing the boundary checks. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: fix kernel BUG in ext4_write_inline_data_end
When the data=journal mount option is used, the ext4_journalled_write_end()
function incorrectly calls ext4_write_inline_data_end() without checking
if the EXT4_STATE_MAY_INLINE_DATA flag is still set on the inode.
If a previous attempt to convert the inline data to an extent failed (e.g.
due to ENOSPC), the EXT4_STATE_MAY_INLINE_DATA flag is cleared, but
the EXT4_INODE_INLINE_DATA flag remains set. In this scenario, the next
call to ext4_write_begin() will not prepare the inline data xattr for
writing, but ext4_journalled_write_end() will incorrectly attempt to write
to it, triggering a BUG_ON(pos + len > EXT4_I(inode)->i_inline_size) in
ext4_write_inline_data() since i_inline_size was not expanded.
Fix this by ensuring that ext4_journalled_write_end() only calls
ext4_write_inline_data_end() if the EXT4_STATE_MAY_INLINE_DATA flag is
set, mirroring the behavior of ext4_write_end() and ext4_da_write_end(). |
| In the Linux kernel, the following vulnerability has been resolved:
vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler
Look up the IRQ index in oct_hw->irqs instead of assuming
irq - irqs[0]. This supports non-contiguous IRQ numbers and
avoids incorrect ring indexing when irqs[0] is not the base. |
| In the Linux kernel, the following vulnerability has been resolved:
virtio: rtc: tear down old virtqueues before restore
virtio_device_restore() resets the device and restores the negotiated
features before calling ->restore(). viortc_freeze() intentionally
leaves the existing virtqueues in place so the alarm queue can still
wake the system, but viortc_restore() immediately calls
viortc_init_vqs() without first deleting those old queues.
If virtqueue reinitialization fails on virtio-pci, the transport error
path can run vp_del_vqs() against a newly allocated vp_dev->vqs array
while vdev->vqs still contains the old virtqueues. vp_del_vqs() then
looks up queue state through the new array and can dereference a NULL
info pointer in vp_del_vq(), crashing the guest kernel during restore.
This can also happen during a non-faulty reinitialization, when one of
the vp_find_vqs_msix() attempts is unsuccessful before a later attempt
would succeed.
Delete the stale virtqueues before rebuilding them. If restore fails
before virtio_device_ready(), reuse the remove path to stop the device.
Once the device is ready, return errors directly instead of deleting the
virtqueues again. |
| In the Linux kernel, the following vulnerability has been resolved:
vhost/vdpa: validate virtqueue index in mmap and fault paths
vhost_vdpa_mmap() and vhost_vdpa_fault() use vma->vm_pgoff as a
virtqueue index for get_vq_notification(), but they do not validate
that the index is smaller than v->nvqs.
The ioctl path already performs both a bounds check and
array_index_nospec(), but the mmap/fault path only checks that the
index fits in u16. This allows an out-of-range queue index to reach
driver-specific get_vq_notification() callbacks.
Fix this by extracting a unified vhost_vdpa_get_vq_notification()
helper that validates the queue index against v->nvqs and applies
array_index_nospec() before calling the driver callback. Both the
mmap and fault paths use this helper, and the bounds checking is
consolidated into a single location.
From source inspection, the most defensible impact is out-of-bounds
access in the callback path, potentially leading to invalid PFN
remaps and crash/DoS. |
| In the Linux kernel, the following vulnerability has been resolved:
vduse: hold vduse_lock across IDR lookup in open path
vduse_dev_open() looks up struct vduse_dev through the IDR and then
acquires dev->lock only after vduse_lock has been dropped.
This leaves a window where a concurrent VDUSE_DESTROY_DEV can remove the
same object from the IDR and free it before the open path locks the
device, leading to a use-after-free.
Close this race by keeping vduse_lock held until dev->lock has been
acquired in the open path, matching the lock ordering already used by
the destroy path. |
| In the Linux kernel, the following vulnerability has been resolved:
NFSD: Handle layout stid in nfsd4_drop_revoked_stid()
nfsd4_drop_revoked_stid() has no SC_TYPE_LAYOUT case, so when a
client sends FREE_STATEID for an admin-revoked layout stid, the
default branch releases cl_lock and returns without unhashing or
releasing the stid. The stid remains in the IDR and on the
per-client list until the client is destroyed.
Remove the layout stid from the per-client list and call
nfs4_put_stid() to drop the creation reference. When the
refcount reaches zero, nfsd4_free_layout_stateid() handles the
remaining cleanup: cancelling the fence worker, removing from
the per-file list, and freeing the slab object. |
| In the Linux kernel, the following vulnerability has been resolved:
ixgbe: do not configure xps for XDP queues
netif_set_xps_queue() should not be called for an XDP Tx queue, since such
queues are not netdev-exposed. On systems with number of CPUs >=64, on E610
adapter, netdev is configured with maximum number queue pairs being 63
(due to MSI-X assignment), but configuring XDP results in 64 XDP queues.
So, during XDP program load, when netif_set_xps_queue() is called for the
last XDP queue, we get a WARNING with a call trace and KASAN report
afterwards (if enabled).
[ 2012.699800] WARNING: net/core/dev.c:2854 at __netif_set_xps_queue+0x116a/0x1e40, CPU#36: xdpsock/103668
[...]
[ 2012.700029] RIP: 0010:__netif_set_xps_queue+0x116a/0x1e40
[ 2012.700035] Code: b6 34 06 48 89 f8 83 e0 07 83 c0 01 40 38 f0 7c 09 40 84 f6 0f 85 03 0a 00 00 0f b7 44 24 40 66 43 89 44 6a 18 e9 01 fb ff ff <0f> 0b e9 f2 ee ff ff 44 8b 44 24 44 45 85 c0 74 50 4d 85 e4 0f 84
[ 2012.700040] RSP: 0018:ffff8882369aeb28 EFLAGS: 00010246
[ 2012.700046] RAX: 0000000000000000 RBX: 000000000000003f RCX: 0000000000000000
[ 2012.700050] RDX: 1ffff1111da3d891 RSI: ffff888120e34250 RDI: ffff8888ed1ec488
[ 2012.700054] RBP: ffff888913281560 R08: 0000000000000000 R09: ffff8888ed1ec000
[ 2012.700058] R10: ffff8888a2e83180 R11: 0000000000000000 R12: 0000000000007fa8
[ 2012.700061] R13: 000000000000003f R14: ffff888120e34854 R15: ffff8889132817c8
[ 2012.700065] FS: 00007fc8ea9ff740(0000) GS:ffff88884cefe000(0000) knlGS:0000000000000000
[ 2012.700069] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2012.700073] CR2: 00007f81c8000020 CR3: 00000002299f8006 CR4: 00000000007726f0
[ 2012.700077] PKRU: 55555554
[ 2012.700080] Call Trace:
[ 2012.700084] <TASK>
[ 2012.700087] ? ktime_get+0x61/0x150
[ 2012.700097] ? usleep_range_state+0x133/0x1b0
[ 2012.700108] ? __pfx_usleep_range_state+0x10/0x10
[ 2012.700114] netif_set_xps_queue+0x31/0x50
[ 2012.700119] ixgbe_configure_tx_ring+0x472/0x920 [ixgbe]
[...]
[ 2012.700486] ixgbe_xdp+0x38f/0x750 [ixgbe]
[...]
[ 2012.701094] BUG: KASAN: slab-out-of-bounds in __netif_set_xps_queue+0x1ac5/0x1e40
[ 2012.701100] Write of size 4 at addr ffff88888d43cff8 by task xdpsock/103668
Skip XPS configuration for XDP Tx queues. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix deadlock cloning inline extent when using flushoncommit
In commit b48c980b6a7e ("btrfs: fix deadlock between reflink and
transaction commit when using flushoncommit") a deadlock was fixed
between reflinks and transaction commits when the fs is mounted with the
flushoncommit option. This happened when we had to copy an inline extent's
data to the destination file. However the issue was fixed only for the
case where the destination offset is 0, it missed the case when the offset
is greater than zero.
Fix this by ensuring we get i_size update whenever we copied an inline
extent's data into the destination file.
Syzbot reported this with the following trace:
INFO: task kworker/u8:3:57 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:3 state:D stack:21600 pid:57 tgid:57 ppid:2 task_flags:0x4208160 flags:0x00080000
Workqueue: writeback wb_workfn (flush-btrfs-129)
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5402 [inline]
__schedule+0x16f9/0x5500 kernel/sched/core.c:7204
__schedule_loop kernel/sched/core.c:7283 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7298
wait_extent_bit fs/btrfs/extent-io-tree.c:905 [inline]
btrfs_lock_extent_bits+0x59c/0x700 fs/btrfs/extent-io-tree.c:2008
btrfs_lock_extent fs/btrfs/extent-io-tree.h:152 [inline]
btrfs_invalidate_folio+0x440/0xc00 fs/btrfs/inode.c:7718
extent_writepage fs/btrfs/extent_io.c:1848 [inline]
extent_write_cache_pages fs/btrfs/extent_io.c:2552 [inline]
btrfs_writepages+0x12f3/0x2410 fs/btrfs/extent_io.c:2684
do_writepages+0x32e/0x550 mm/page-writeback.c:2571
__writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764
writeback_sb_inodes+0x97f/0x1980 fs/fs-writeback.c:2056
wb_writeback+0x445/0xb00 fs/fs-writeback.c:2241
wb_do_writeback fs/fs-writeback.c:2388 [inline]
wb_workfn+0x3fd/0xf20 fs/fs-writeback.c:2428
process_one_work+0x98b/0x1630 kernel/workqueue.c:3318
process_scheduled_works kernel/workqueue.c:3401 [inline]
worker_thread+0xb49/0x1140 kernel/workqueue.c:3482
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
INFO: task syz.0.145:8523 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.145 state:D stack:22752 pid:8523 tgid:8522 ppid:5850 task_flags:0x400140 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5402 [inline]
__schedule+0x16f9/0x5500 kernel/sched/core.c:7204
__schedule_loop kernel/sched/core.c:7283 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7298
wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227
__writeback_inodes_sb_nr+0x24c/0x2d0 fs/fs-writeback.c:2847
try_to_writeback_inodes_sb+0x9a/0xc0 fs/fs-writeback.c:2895
btrfs_start_delalloc_flush fs/btrfs/transaction.c:2182 [inline]
btrfs_commit_transaction+0x813/0x2fc0 fs/btrfs/transaction.c:2371
btrfs_sync_file+0xdf4/0x1230 fs/btrfs/file.c:1822
generic_write_sync include/linux/fs.h:2663 [inline]
btrfs_do_write_iter+0x6a9/0x840 fs/btrfs/file.c:1473
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x629/0xba0 fs/read_write.c:688
ksys_write+0x156/0x270 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5a0bdece59
RSP: 002b:00007f5a0b446028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5a0c065fa0 RCX: 00007f5a0bdece59
RDX: 000000000000029f RSI: 0000200000
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
net: mpls: initialize rtm_tos in mpls_getroute()
mpls_getroute() builds the RTM_NEWROUTE reply to an RTM_GETROUTE
request by filling a struct rtmsg allocated from an skb whose data
area is not zeroed (alloc_skb(NLMSG_GOODSIZE, ...)). It sets every
field of the header except rtm_tos:
r = nlmsg_data(nlh);
r->rtm_family = AF_MPLS;
r->rtm_dst_len = 20;
r->rtm_src_len = 0;
r->rtm_table = RT_TABLE_MAIN;
r->rtm_type = RTN_UNICAST;
r->rtm_scope = RT_SCOPE_UNIVERSE;
r->rtm_protocol = rt->rt_protocol;
r->rtm_flags = 0;
struct rtmsg has no padding, so the one uninitialised byte rtm_tos
(offset 3) is copied straight to user space on recvmsg(), leaking a
byte of uninitialised heap memory. This is in contrast to
mpls_dump_route(), which fills the very same header and does set
rtm_tos = 0.
Initialize rtm_tos to 0, matching mpls_dump_route().
Reproduced with KMSAN by adding an MPLS route and issuing a
non-RTM_F_FIB_MATCH RTM_GETROUTE for its label:
BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x36c/0x33f0
_copy_to_iter+0x36c/0x33f0
__skb_datagram_iter+0x196/0x12c0
skb_copy_datagram_iter+0x5b/0x210
netlink_recvmsg+0x37b/0xef0
...
Uninit was created at:
__alloc_skb+0x8ca/0x10e0
mpls_getroute+0x1280/0x3a40
rtnetlink_rcv_msg+0x1138/0x15a0
...
Byte 19 of 64 is uninitialized
(byte 19 = nlmsghdr(16) + rtmsg offset 3 = rtm_tos) |
| In the Linux kernel, the following vulnerability has been resolved:
mm/slab: prevent unbounded recursion in free path with new kmalloc type
Commit 280ea9c3154b ("mm/slab: avoid allocating slabobj_ext array from
its own slab") avoided recursive allocation of obj_exts from kmalloc
caches of the same size, by bumping the obj_exts array's allocation
size whenever the array size equals the size of the object being
allocated.
However, as reported by Danielle Costantino and Shakeel Butt,
even slabs from kmalloc caches of different sizes can form a cycle
by allocating obj_exts arrays from each other [1]:
What happened: a KMALLOC_NORMAL slab's obj_exts array (used by
allocation profiling / memcg accounting) is itself kmalloc()'d from a
KMALLOC_NORMAL cache, so the "slab holds another slab's obj_exts array"
relation can form cycles. With sizeof(struct slabobj_ext) == 16 and
the host's geometry:
- kmalloc-512 has 64 objects/slab -> array is 64*16 == 1024 bytes,
served from kmalloc-1k;
- kmalloc-1k has 32 objects/slab -> array is 32*16 == 512 bytes,
served from kmalloc-512.
A kmalloc-512 slab and a kmalloc-1k slab therefore hold each other's
obj_exts array. Discarding one frees the other's array, which empties
and discards that slab, which frees the first's array, and so on:
__free_slab() -> free_slab_obj_exts() -> kfree() -> discard_slab() ->
__free_slab() recurses along the cycle until the stack is exhausted.
With memory allocation profiling, this allows unbounded recursion
in the free path and led to a stack overflow on a production host in
the Meta fleet [1]:
BUG: TASK stack guard page was hit
Oops: stack guard page
RIP: 0010:kfree+0x8/0x5d0
Call Trace:
__free_slab+0x66/0xc0
kfree+0x3f0/0x5d0
... ( ~125x __free_slab <-> kfree ) ...
<kernel driver freeing a resource>
do_syscall_64
It is proposed [1] to resolve this issue by always serving the obj_exts
array allocation from kmalloc caches (or large kmalloc) of sizes larger
than the object size. However, as pointed out by Vlastimil Babka [2],
this can waste an excessive amount of memory as slabs from large
kmalloc sizes (e.g. kmalloc-8k) generally need obj_exts arrays much
smaller than the object size.
Therefore, rather than bumping the size, let us take a different
approach; disallow formation of cycles between kmalloc types when
allocating obj_exts arrays. Currently, all obj_exts arrays are served
from normal kmalloc caches. Cycles cannot be created if obj_exts arrays
of normal kmalloc caches are served from a special kmalloc type that can
never have obj_exts arrays.
To achieve this, create a new kmalloc type called KMALLOC_NO_OBJ_EXT.
KMALLOC_NO_OBJ_EXT caches are created with SLAB_NO_OBJ_EXT flag when
either 1) memory allocation profiling is not permanently disabled,
or 2) kmalloc types with a priority higher than KMALLOC_CGROUP are
aliased with KMALLOC_NORMAL.
Sheaf bootstrapping for KMALLOC_NO_OBJ_EXT caches now must be deferred
because allocation of a barn can trigger obj_exts array allocation of
normal kmalloc caches when the KMALLOC_NO_OBJ_EXT cache for that size
is not ready yet. For simplicity, perform bootstrapping of sheaves for
all kmalloc caches later.
Introduce a new slab alloc flag, SLAB_ALLOC_NO_OBJ_EXT, to prevent
allocation of obj_exts arrays, and let kmalloc_slab() override the type
to KMALLOC_NO_OBJ_EXT when specified. Note that kmalloc_type() remains
unchanged because kmalloc_flags() bypasses the kmalloc fastpath.
Do not pass SLAB_ALLOC_NO_RECURSE to kmalloc_flags() in
alloc_slab_obj_exts() and instead use SLAB_ALLOC_NO_OBJ_EXT only when
the objects are allocated from normal kmalloc caches. While this
prevents unbounded recursive allocation of obj_exts, it allows
KMALLOC_NO_OBJ_EXT caches to have sheaves.
Since sheaf allocations specify SLAB_ALLOC_NO_RECURSE that prevents
allocation of both sheaves and obj_exts arrays, the recursion depth
is bounded.
obj_exts arrays for non-
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
thunderbolt: Prevent XDomain delayed work use-after-free on disconnect
tb_xdp_handle_request() runs on system_wq and queues
xd->state_work via queue_delayed_work() in three request handlers:
PROPERTIES_CHANGED_REQUEST, UUID_REQUEST (via start_handshake),
and LINK_STATE_CHANGE_REQUEST. Similarly, update_xdomain() queues
xd->properties_changed_work when local properties change.
Concurrently, tb_xdomain_remove() calls stop_handshake() which does
cancel_delayed_work_sync() on both delayed works. Later,
tb_xdomain_unregister() calls device_unregister() which eventually
frees the xdomain. Since commit 559c1e1e0134 ("thunderbolt: Run
tb_xdp_handle_request() in system workqueue") moved the request
handler off tb->wq, the handler and the remove path are no longer
serialized. If queue_delayed_work() executes after
cancel_delayed_work_sync() but before the xdomain is freed, the
delayed work fires on a freed object.
Add xd->removing that tb_xdomain_remove() sets under xd->lock
before calling stop_handshake(). Each external queue site holds
the same lock and checks removing before calling
queue_delayed_work(). This provides the mutual exclusion needed:
either the queue site acquires the lock first and queues work that
the subsequent cancel will see, or the remove path acquires the
lock first and the queue site observes removing == true and skips
the queue. |
