| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: remove stale channels from all sessions on teardown
ksmbd_sessions_deregister() removes a connection's channels from other
sessions' channel lists only while conn->binding is still set:
if (conn->binding) {
hash_for_each_safe(sessions_table, ...)
ksmbd_chann_del(conn, sess);
}
conn->binding is a transient flag: it is cleared once a binding
SESSION_SETUP completes, and also by a subsequent non-binding
SESSION_SETUP on the same connection (a reauthentication on a bound
channel, or a new SessionId==0 setup). A connection that has bound a
channel into another session's ksmbd_chann_list and then clears
conn->binding leaves that channel behind when it disconnects: the
channel, whose chann->conn points at the now freed struct ksmbd_conn,
stays on the owner session's list.
When the owning connection later tears down, the second loop
dereferences the stale channel:
xa_for_each(&sess->ksmbd_chann_list, chann_id, chann)
if (chann->conn != conn)
ksmbd_conn_set_exiting(chann->conn); /* freed */
which is a use-after-free write into the freed ksmbd_conn (the same
stale channel is also walked by show_proc_session() through /proc). The
session is leaked as well, because its channel list never empties.
Remove the conn->binding gate so a connection always removes its
channels from every session on teardown. |
| In the Linux kernel, the following vulnerability has been resolved:
llc: fix skb UAF and leaks on llc_mac_hdr_init() failure
In llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr(), if llc_mac_hdr_init()
fails, kfree_skb(skb) is called instead of kfree_skb(nskb). This leaks
the newly allocated nskb, reads from the freed skb via LLC_I_GET_NR(pdu),
and double-frees skb when llc_conn_state_process() drops its reference.
In llc_sap_action_send_xid_r() and llc_sap_action_send_test_r(), nskb is
leaked if llc_mac_hdr_init() returns an error.
Free nskb in all three error paths. |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: prevent collapsing skbs across boundary in rtx queue
tcp_write_collapse_fence() sets TCP_SKB_CB(skb)->eor = 1 on
tcp_write_queue_tail(sk) to prevent skbs queued after a switch to
device encryption from being collapsed into earlier skbs.
The fence is a no-op if all earlier data has already been transmitted
when the switch happens: sk->sk_write_queue is empty. The not yet
acknowledged earlier skbs wait in sk->tcp_rtx_queue with eor 0.
On a subsequent retransmit or SACK shift, tcp_retrans_try_collapse() or
tcp_shift_skb_data() can then merge an skb queued after the switch into
one queued before it.
Both users of the fence are affected:
- psp: devices only encrypt skbs with skb->decrypted set. The merged skb
keeps decrypted = 0 from the earlier skb, so merged data sent after
psp_sock_assoc_set_tx() is retransmitted in cleartext.
- tls device offload: the merged skb straddles the start marker set in
tls_set_device_offload(). The software fallback (fill_sg_in() returns
-EINVAL) and the mlx5, nfp and funeth drivers cannot handle such an
skb and drop it. Every retransmit rebuilds the same skb, so the
connection stalls.
Fix this in two places, for defense in depth:
1. Fall back to tcp_rtx_queue_tail(sk) in tcp_write_collapse_fence()
when tcp_write_queue_tail(sk) is NULL.
2. Check !skb_cmp_decrypted(to, from) in tcp_skb_can_collapse(), as
tcp_skb_can_collapse_rx() does on receive. skb_shift(), which both
collapse paths call, already has a DEBUG_NET_WARN_ON_ONCE() for this
condition. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: discard the rest of the packet on a stale-cookie error
When an association is in COOKIE-ECHOED state and the peer sends a
bundled [ERROR(Stale Cookie)][DATA] packet from one of its non-primary
addresses, processing the ERROR chunk takes the non-fatal stale-cookie
retry path sctp_sf_do_5_2_6_stale(), which queues
SCTP_CMD_DEL_NON_PRIMARY while keeping the association alive.
sctp_cmd_del_non_primary() removes every non-primary transport -
including the very transport this packet arrived on, which is still
referenced by the receive lookup and shared by all chunks of the
packet via chunk->transport.
sctp_assoc_rm_peer() does redirect asoc->peer.last_data_from away from
the removed transport, but right afterwards the bundled DATA chunk
makes sctp_assoc_bh_rcv() re-register
asoc->peer.last_data_from = chunk->transport unconditionally, undoing
the redirection with the just-removed transport.
Once the packet is done, the receive reference is dropped and the
transport is RCU-freed, while the surviving association keeps the
dangling last_data_from. A later FWD-TSN (or the delayed SACK timer)
makes sctp_gen_sack() dereference it (->param_flags and friends), and
sctp_make_sack()/sctp_outq_select_transport() may write to the freed
object and link it into the live transport list. This is a
use-after-free triggerable by any malicious SCTP peer (or a local
unprivileged user acting as one) with no capabilities required:
BUG: KASAN: slab-use-after-free in sctp_do_sm+0x498a/0x5660
Read of size 4 at addr ffff88800e1e356c by task poc/115
Call Trace: sctp_do_sm <- sctp_assoc_bh_rcv <- sctp_inq_push <-
sctp_rcv <- ip_protocol_deliver_rcu <- ip_rcv
Allocated: sctp_transport_new <- sctp_assoc_add_peer <-
sctp_process_init (INIT-ACK processing)
Freed: kfree <- sctp_transport_destroy_rcu <- rcu_core
(call_rcu queued by sctp_transport_put at end of sctp_rcv)
The buggy address is located 364 bytes inside of freed 1024-byte
region [ffff88800e1e3400, ffff88800e1e3800), cache kmalloc-1k
Note that commit 03a9d10ecf71 ("sctp: drop a chunk if its transport
was removed") only covers the window between the receive lookup and
the chunk processing (e.g. an ASCONF DEL-IP racing the socket backlog);
here the transport is removed *while* the packet is being processed,
by an earlier chunk of the same packet, so the drop in sctp_inq_push()
does not reach this path. Verified with the bundled [ERROR(Stale
Cookie)][DATA] + FWD-TSN reproducer: the KASAN report above still
fires with that commit applied, and is gone with this patch on top.
Fix it by discarding the rest of the packet on this path, as suggested
by Xin. After the stale-cookie ERROR has sent the association back to
COOKIE-WAIT and removed the non-primary transports, the remaining
chunks of the packet can only run against the restarted handshake
while referencing the removed arrival transport through
chunk->transport: besides the last_data_from registration above,
sctp_cmd_setup_t2() and the sctp_make_*() reply builders would also
copy that pointer into association-lifetime state that
sctp_assoc_rm_peer() has already sanitized. Let the peer retransmit
them, in line with what sctp_inq_push() does for chunks whose
transport was removed before processing. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: fs/xattr: don't assume the inode is locked in path_unlink/path_rmdir
bpf_lsm_has_d_inode_locked() makes the verifier rewrite
bpf_[set|remove]_dentry_xattr() to the _locked variants, which assume
that the caller already holds the inode's i_rwsem. The path_unlink and
path_rmdir hooks are listed, but security_path_unlink() and
security_path_rmdir() run before vfs_unlink()/vfs_rmdir() take the
victim inode's i_rwsem, so a sleepable BPF LSM program attached to
either hook mutates the victim's xattrs without the lock held.
Drop the two path hooks from d_inode_locked_hooks so that the verifier
keeps the locking bpf_[set|remove]_dentry_xattr() variants, which take
the lock themselves. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: do not let ipv6_find_hdr() return an offset past the packet end
ipv6_find_hdr() walks the extension header chain, skipping each header by
the length that header itself declares. ipv6_optlen() returns up to 2048,
and the skip is never checked against skb->len, so the offset stored in
*offset can point past the end of the packet.
openvswitch installs that offset as the transport header, and
update_ipv6_checksum() then reads and writes the transport checksum field
out of bounds:
BUG: KASAN: slab-use-after-free in inet_proto_csum_replace16+0x445/0x470
Read of size 2 at addr ffff88810b754b06 by task ovs_ipv6_oob/629
CPU: 4 UID: 1000 PID: 629 Comm: ovs_ipv6_oob Tainted: G N 7.3.0-rc3+ #348
Call Trace:
inet_proto_csum_replace16+0x445/0x470
set_ipv6_addr+0x3dd/0x460
do_execute_actions+0x6a3d/0x7c40
ovs_execute_actions+0xfd/0x480
ovs_packet_cmd_execute+0xc38/0xf20
genl_rcv_msg+0x59e/0x870
netlink_rcv_skb+0x18b/0x450
genl_rcv+0x2d/0x40
netlink_unicast+0x6bc/0xa20
The buggy address belongs to the object at ffff88810b754980
which belongs to the cache skbuff_small_head of size 704
The buggy address is located 390 bytes inside of
freed 704-byte region [ffff88810b754980, ffff88810b754c40)
Other callers use that offset too, so bound it here rather than in one
caller.
Reject a header whose declared length does not fit in the packet.
ipv6_find_hdr() already fails with -EBADMSG on a malformed chain, so this
adds no new failure mode. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: fix use-after-free and multi-container gap in kfd_dev_mapping
kfd_dev_mapping caches the address_space of the first /dev/kfd opener
so that the GPU reset path can call unmap_mapping_range() to zap all
userspace mappings of doorbell and MMIO ranges. This design has two
bugs that both manifest under SRIOV with multiple containers:
1. Use-after-free / rwsem deadlock. The cached pointer refers to an
inode owned by the first opener's container. When that container
exits and its inode is released, kfd_dev_mapping becomes a dangling
pointer. A subsequent GPU reset dereferences it inside
unmap_mapping_range(), which takes i_mmap_rwsem on the freed inode,
causing a hard hang observable as an uninterruptible rwsem wait.
2. Multi-container gap. Only the first opener's address_space is cached;
VMAs created by later openers live in a different address_space and
are never reached by unmap_mapping_range(). After a GPU reset those
stale mappings keep doorbell and MMIO pages accessible to guest
userspace with no GPU behind them, risking PCIe transaction timeouts
and NMI panics.
Fix both bugs with the same approach used by DRM core (drm_drv.c):
create a private pseudo-filesystem at module init time and allocate one
anonymous inode from it. In kfd_open() redirect every opener's
file->f_mapping to that inode's address_space. The inode is
module-owned, lives exactly as long as the amdgpu module, and collects
VMAs from all openers in one address_space. A single
unmap_mapping_range() call in the reset path then correctly reaches
every container's mappings with no dangling pointer risk.
The hang manifests as an NMI backtrace on the GPU reset workqueue stuck
spinning in rwsem_down_read_slowpath() with a corrupted i_mmap_rwsem:
Workqueue: amdgpu-reset-dev xgpu_ai_mailbox_flr_work [amdgpu]
Call Trace:
<TASK>
kvm_wait+0x1f/0x40
__pv_queued_spin_lock_slowpath+0x31d/0x3a0
_raw_spin_lock_irq+0x51/0x80
rwsem_down_read_slowpath+0xb3/0x550
down_read+0x48/0xd0
unmap_mapping_range+0x71/0x140
kfd_dev_unmap_mapping_range+0x5b/0x140 [amdgpu]
amdgpu_amdkfd_clear_kfd_mapping+0xd8/0x190 [amdgpu]
amdgpu_device_gpu_recover+0x232/0x450 [amdgpu]
xgpu_ai_mailbox_flr_work+0xb5/0xc0 [amdgpu]
process_one_work+0x18e/0x3e0
worker_thread+0x2e3/0x420
kthread+0x10a/0x230
(cherry picked from commit 1128b4a52de1572e87431de837fd9850cb99542c) |
| In the Linux kernel, the following vulnerability has been resolved:
drm/nouveau/dmem: pin VRAM for the whole registered range
Commit c32287471077 ("gpu/drm/nouveau: enable THP support for GPU memory
migration") grew the device-private region that
nouveau_dmem_chunk_alloc() registers from DMEM_CHUNK_SIZE to
DMEM_CHUNK_SIZE * NR_CHUNKS, but left the VRAM buffer object backing that
region at DMEM_CHUNK_SIZE.
nouveau_dmem_page_addr() returns chunk->bo->offset plus the page's offset
within the registered region, so every page past the first chunk resolves
to VRAM outside the buffer object.
Size the buffer object to the region it backs. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/nouveau/uvmm: fix UAF in nouveau_uvmm_sm when BO is in TTM_PL_SYSTEM
nouveau_uvmm_sm() calls op_map(), which passes bo->resource through
nouveau_mem() to nouveau_uvma_map(). nouveau_uvmm_vmm_map() then reads
mem->mem.type.
But this is only valid when bo->resource is backed by struct nouveau_mem,
as is the case for VRAM and TT resources. If the BO is left in
TTM_PL_SYSTEM, bo->resource is only a struct ttm_resource. Treating it
as struct nouveau_mem makes the mem->mem.type read past the end of the
resource, causing a KASAN: slab-use-after-free Read in nouveau_uvmm_sm
report:
BUG: KASAN: slab-use-after-free in nouveau_uvmm_vmm_map drivers/gpu/drm/nouveau/nouveau_uvmm.c:152 [inline]
BUG: KASAN: slab-use-after-free in nouveau_uvma_map drivers/gpu/drm/nouveau/nouveau_uvmm.c:199 [inline]
BUG: KASAN: slab-use-after-free in op_map drivers/gpu/drm/nouveau/nouveau_uvmm.c:849 [inline]
BUG: KASAN: slab-use-after-free in nouveau_uvmm_sm.constprop.0+0x6ab/0x900 drivers/gpu/drm/nouveau/nouveau_uvmm.c:903
Read of size 1 at addr ffff888127d3e3a0 by task kworker/0:1/11
CPU: 0 UID: 0 PID: 11 Comm: kworker/0:1 Not tainted 7.2.0 #5 PREEMPT(lazy)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: nouveau_sched_wq_2224 drm_sched_run_job_work
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x95/0xe0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xcb/0x5a0 mm/kasan/report.c:482
kasan_report+0xca/0x100 mm/kasan/report.c:595
nouveau_uvmm_vmm_map drivers/gpu/drm/nouveau/nouveau_uvmm.c:152 [inline]
nouveau_uvma_map drivers/gpu/drm/nouveau/nouveau_uvmm.c:199 [inline]
op_map drivers/gpu/drm/nouveau/nouveau_uvmm.c:849 [inline]
nouveau_uvmm_sm.constprop.0+0x6ab/0x900 drivers/gpu/drm/nouveau/nouveau_uvmm.c:903
nouveau_uvmm_sm_unmap drivers/gpu/drm/nouveau/nouveau_uvmm.c:932 [inline]
nouveau_uvmm_bind_job_run+0xd6/0x250 drivers/gpu/drm/nouveau/nouveau_uvmm.c:1532
nouveau_job_run drivers/gpu/drm/nouveau/nouveau_sched.c:350 [inline]
nouveau_sched_run_job+0x62/0xd0 drivers/gpu/drm/nouveau/nouveau_sched.c:364
drm_sched_run_job_work+0x356/0xa10 drivers/gpu/drm/scheduler/sched_main.c:1061
process_one_work+0x8a5/0x1900 kernel/workqueue.c:3322
process_scheduled_works kernel/workqueue.c:3405 [inline]
worker_thread+0x5dd/0xd80 kernel/workqueue.c:3486
kthread+0x31d/0x420 kernel/kthread.c:436
ret_from_fork+0x662/0x940 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Allocated by task 2224 on cpu 0 at 66.550027s:
kasan_save_stack+0x24/0x50 mm/kasan/common.c:57
kasan_save_track+0x17/0x60 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5334 [inline]
__kmalloc_noprof+0x304/0x7c0 mm/slub.c:5359
_kmalloc_noprof include/linux/slab.h:992 [inline]
dma_resv_list_alloc+0x27/0x90 drivers/dma-buf/dma-resv.c:106
dma_resv_reserve_fences+0x60e/0xa30 drivers/dma-buf/dma-resv.c:205
ttm_bo_alloc_resource+0x12c/0xbd0 drivers/gpu/drm/ttm/ttm_bo.c:721
ttm_bo_validate+0x1bc/0x4a0 drivers/gpu/drm/ttm/ttm_bo.c:856
ttm_bo_init_reserved+0x2c3/0x570 drivers/gpu/drm/ttm/ttm_bo.c:970
nouveau_bo_init+0x159/0x2c0 drivers/gpu/drm/nouveau/nouveau_bo.c:359
nouveau_gem_new+0x234/0x5f0 drivers/gpu/drm/nouveau/nouveau_gem.c:272
nouveau_gem_ioctl_new+0x1eb/0x420 drivers/gpu/drm/nouveau/nouveau_gem.c:352
drm_ioctl_kernel+0x192/0x350 drivers/gpu/drm/drm_ioctl.c:817
drm_ioctl+0x4f8/0xb40 drivers/gpu/drm/drm_ioctl.c:914
nouveau_drm_ioctl+0xea/0x2c0 drivers/gpu/drm/nouveau/nouveau_drm.c:1338
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x180/0x1d0 fs/ioctl.c:583
do_syscall_x64 ar
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
drm/nouveau: fix double-free in nvif_vmm_dtor
On failure, nouveau_cli_init() calls nouveau_cli_fini() to tear
the client down. Then, nouveau_drm_open() also enters into its
cleanup path and calls nouveau_cli_fini() AGAIN. nouveau_cli_fini()
calls nouveau_vmm_fini():
void
nouveau_vmm_fini(struct nouveau_vmm *vmm)
{
nouveau_svmm_fini(&vmm->svmm);
nvif_vmm_dtor(&vmm->vmm);
vmm->cli = NULL;
}
Inside nvif_vmm_dtor(), vmm->page is freed unconditionally:
void
nvif_vmm_dtor(struct nvif_vmm *vmm)
{
kfree(vmm->page);
nvif_object_dtor(&vmm->object);
}
vmm->page is never cleared after being freed, so the second call of
nvif_vmm_dtor() will cause a double-free.
Found by fuzzing the nouveau driver with a modified Syzkaller:
BUG: KASAN: double-free in nvif_vmm_dtor+0x31/0x50 drivers/gpu/drm/nouveau/nvif/vmm.c:194
Free of addr ffff888010fcdc30 by task syz.0.173/2567
CPU: 1 UID: 0 PID: 2567 Comm: syz.0.173 Not tainted 7.2.0 #24 PREEMPT(lazy)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x95/0xe0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xcb/0x5a0 mm/kasan/report.c:482
kasan_report_invalid_free+0xaa/0xd0 mm/kasan/report.c:557
check_slab_allocation+0xe4/0x110 mm/kasan/common.c:235
kasan_slab_pre_free include/linux/kasan.h:199 [inline]
slab_free_hook mm/slub.c:2622 [inline]
slab_free mm/slub.c:6377 [inline]
kfree+0x192/0x590 mm/slub.c:6692
nvif_vmm_dtor+0x31/0x50 drivers/gpu/drm/nouveau/nvif/vmm.c:194
nouveau_vmm_fini+0x16/0x50 drivers/gpu/drm/nouveau/nouveau_vmm.c:127
nouveau_cli_fini+0x10e/0x210 drivers/gpu/drm/nouveau/nouveau_drm.c:225
nouveau_drm_open+0x24e/0x740 drivers/gpu/drm/nouveau/nouveau_drm.c:1255
drm_file_alloc+0x5f2/0xad0 drivers/gpu/drm/drm_file.c:176
drm_open_helper+0x1d7/0x4a0 drivers/gpu/drm/drm_file.c:335
drm_open+0x190/0x3d0 drivers/gpu/drm/drm_file.c:388
drm_stub_open+0x1f2/0x460 drivers/gpu/drm/drm_drv.c:1211
chrdev_open+0x21c/0x660 fs/char_dev.c:411
do_dentry_open+0x59d/0x12b0 fs/open.c:947
vfs_open+0x82/0x390 fs/open.c:1052
do_open fs/namei.c:4700 [inline]
path_openat+0x2345/0x3420 fs/namei.c:4863
do_file_open+0x207/0x460 fs/namei.c:4892
do_sys_openat2+0xd1/0x1d0 fs/open.c:1368
do_sys_open fs/open.c:1374 [inline]
__do_sys_openat fs/open.c:1390 [inline]
__se_sys_openat fs/open.c:1385 [inline]
__x64_sys_openat+0x144/0x200 fs/open.c:1385
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x690 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc6d687594d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc6d5295008 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fc6d6b06180 RCX: 00007fc6d687594d
RDX: 0000000000022501 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007fc6d691c303 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc6d6b06218 R14: 00007fc6d6b06180 R15: 00007ffd9451d760
</TASK>
Allocated by task 2567 on cpu 1 at 163.593900s:
kasan_save_stack+0x24/0x50 mm/kasan/common.c:57
kasan_save_track+0x17/0x60 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5334 [inline]
__kmalloc_noprof+0x304/0x7c0 mm/slub.c:5359
_kmalloc_noprof include/linux/slab.h:992 [inline]
nvif_vmm_ctor+0x3c0/0x7e0 drivers/gpu/drm/nouveau/nvif/vmm.c:237
nouveau_vmm_init+0x40/0x90 drivers/gpu/drm/nouveau/nouveau_vmm.c:134
nouveau_cli_init+0x7b9/0
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
drm/nouveau: RCU-free the scheduler-containing nouveau_sched
struct nouveau_sched embeds a struct drm_gpu_scheduler (base).
nouveau_sched_destroy() calls nouveau_sched_fini() (which does
drm_sched_fini(&sched->base)) and then frees the object with plain
kfree(sched).
drm_sched_fence_get_timeline_name() returns fence->sched->name, and the
scheduler fence keeps a .release callback so it is not ops-detached on
signalling. A finished fence exported to userspace via drm_syncobj /
sync_file therefore keeps pointing at &sched->base after nouveau_sched_destroy(),
and a later get_timeline_name() -- reachable unprivileged through
SYNC_IOC_FILE_INFO -- dereferences freed memory (KASAN slab-use-after-free
read).
Per the dma-fence lifetime contract the exporter must keep the data backing a
signalled fence alive for an RCU grace period. Free the scheduler-containing
object with kfree_rcu() instead of kfree(). |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/vm: nuke PTs only after unlinking contested VMAs
In xe_vm_close_and_put(), external-BO VMAs are queued on the contested
list for deferred destruction via xe_vma_destroy_unlocked(). However,
xe_vm_pt_destroy() was previously invoked before processing contested
VMAs, destroying vm->pt_root while those VMAs were still linked to their
respective buffer objects (vm_bo->list.gpuva).
If a concurrent thread evicts one of those shared buffer objects,
xe_bo_trigger_rebind() holding only bo->resv walks the BO's VMAs and, in
fault mode, calls xe_vm_invalidate_vma() -> xe_pt_zap_ptes(). Because
vm->pt_root[tile->id] is already NULL, dereferencing pt->level causes a
NULL ptr deref.
Fix this by deferring xe_vm_free_scratch() and xe_vm_pt_destroy() until
after all contested VMAs have been unlinked and destroyed.
User is reporting hitting a NULL ptr deref in xe_pt_zap_ptes(), which
could be explained by this race.
(cherry picked from commit c2863648959489767f08892fd6e90577d2ea0b6a) |
| In the Linux kernel, the following vulnerability has been resolved:
mm/rmap: fix missing barrier between anon_vma init and vma->anon_vma publish
On arm64 server, we find that a task trying to grab the anon_vma lock
triggers hungtask.
INFO: task main:2354726 blocked for more than 120 seconds.
Tainted: G E 5.10.0-0021.aarch64 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:main state:D stack: 0 pid:2354726 ppid:2350673 flags:0x00000a01
Call trace:
__switch_to+0x7c/0xbc
__schedule+0x3b4/0x8a0
schedule+0x50/0xe0
rwsem_down_write_slowpath+0x3cc/0x6cc
down_write+0x60/0x260
__anon_vma_prepare+0x6c/0x210
do_anonymous_page+0x258/0x660
handle_pte_fault+0x188/0x214
__handle_mm_fault+0x1b0/0x380
handle_mm_fault+0xf4/0x284
do_page_fault+0x19c/0x494
do_translation_fault+0xcc/0xf8
do_mem_abort+0x48/0xac
el0_da+0x44/0x80
el0_sync_handler+0x88/0xb4
el0_sync+0x160/0x180
After analyzing the vmcore, we found the anon_vma->root->rwsem.count is
-1. There is another anon_vma whose anon_vma->root->rwsem.count is 1, the
anon_vma->root->rwsem.owner shows the lock is held, but the stack of the
task shows the task doesn't hold the anon_vma lock.
After adding more debugging info, we found __anon_vma_prepare() reuses
anon_vma and triggers the UAF of anon_vma->root due to missing memory
barrier, leading to locking and unlocking two different anon_vma->root,
thus leading to an anon_vma will never be unlocked, and another anon_vma
couldn't be locked anymore.
This race requires two adjacent VMAs that are not merged but are
anon_vma-compatible (e.g., they differ in VMA_ACCESS_FLAGS that can be
changed by mprotect()). Two threads fault on each VMA concurrently, both
calling __anon_vma_prepare() with only mmap_lock held for reading.
THREAD A THREAD B
__anon_vma_prepare __anon_vma_prepare
find_mergeable_anon_vma() -> NULL
anon_vma = anon_vma_alloc();
anon_vma->root = anon_vma;
// the two stores may be reordered
vma->anon_vma = anon_vma;
// finds A's anon_vma
anon_vma = find_mergeable_anon_vma(vma);
anon_vma_lock_write(anon_vma);
// may still see the old root
down_write(&anon_vma->root->rwsem);
anon_vma_unlock_write(anon_vma);
// see the new root, never unlock old
up_write(&anon_vma->root->rwsem);
thread A triggers page fault and calls __anon_vma_prepare() to prepare
anon_vma for the faulting vma. __anon_vma_prepare() allocates and
initializes a new anon_vma, and then publishes it to the vma with a plain
store. anon_vma_prepare() only requires the mmap_lock to be held for
reading, so two threads can fault on adjacent VMAs at the same time.
While thread A publishes a new anon_vma, thread B could find the anon_vma
via find_mergeable_anon_vma() and then locks anon_vma->root->rwsem.
The store to anon_vma->root in anon_vma_alloc() and the store to
vma->anon_vma can be reordered. The anon_vma_lock_write() and spin_lock()
only provide acquire semantics, which do not prevent prior stores from
being reordered after them. The release semantics of the corresponding
spin_unlock() and anon_vma_unlock_write() come too late, the store to
vma->anon_vma is already published before they take effect. As a result,
thread B can observe the following order:
vma->anon_vma = anon_vma;
anon_vma->root = anon_vma;
The anon_vma slab is SLAB_TYPESAFE_BY_RCU, so a newly allocated anon_vma
may reuse memory from a previously freed one. The constructor
(anon_vma_ctor) does not reset anon_vma->root, and __put_anon_vma()
doesn't clear it either, so the old root value persists until
anon_vma_alloc() overwrites it. If that store isn't v
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
HID: alps: fix use-after-free on input2 registration failure
alps_input_configured() stores data->input2 before calling
input_register_device(). If registration fails, input_free_device()
frees the input device but data->input2 still points to the freed memory.
alps_input_configured() calls hid_hw_open() before allocating input2, so
URBs are already active and raw_event can fire during the failure window.
A U1_SP_ABSOLUTE_REPORT_ID report arriving then causes u1_raw_event()
to dereference the freed data->input2 -> use-after-free.
Fix by only storing input2 into drvdata after successful registration
and adding a NULL guard in the raw_event path. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: wacom: fix OOB read in wacom_wac_pen_serial_enforce()
The 'wacom_wac_pen_serial_enforce()' function may calculate and pass an
invalid offset to hid_field_extract(), resulting in memory reads at
incorrect addresses -- possibly beyond the end of the report. If a
field in the HID descriptor lists more usages than its Report Count
actually reserves space for, the function's inner 'j' will walk past
the end of the field:
for (i = 0; i < report->maxfield; i++) {
for (j = 0; j < report->field[i]->maxusage; j++) {
...
value = hid_field_extract(hdev, raw_data + 1,
offset + j * size, size);
A descriptor listing 12288 usages against Report Count 1 has the loop
extract the usage at index 12287 from bit offset 98296 -- about 12 KB
past a 2-byte received report. The value is stored in
wacom_wac->serial[0] and can reach userspace as an MSC_SERIAL event,
making this an information disclosure.
Clamp the loop to field->report_count, the number of value slots the
report holds. Value slots past the last declared usage are still
scanned; they reuse that usage (HID 1.11, 6.2.2.8).
Verified on v6.12.105 with a UHID reproducer: a 2-byte report from
such a descriptor trips KASAN before the patch and not after it. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: fix swapped IPv6 IPsec policy masks
IPv6 XFRM policies may use different source and destination prefix
lengths. mlx5e_ipsec_policy_mask() builds the corresponding masks
independently, but setup_fte_addr6() installs each mask in the opposite
address field.
When the prefix lengths differ, this makes the source match use the
destination prefix and the destination match use the source prefix. The
resulting hardware rule can both miss traffic covered by the policy and
match traffic outside it.
Install each mask in its corresponding match field. |
| In the Linux kernel, the following vulnerability has been resolved:
net: openvswitch: conntrack: avoid modifying shared unconfirmed ct entry
In a case where skb with an unconfirmed ct entry gets cloned, we may
end up committing both but with different sets of extensions.
The series of events:
1. The first clone wants to commit and runs the helpers wiring up
the extension pointer into the expectation list.
2. Then it looses the confirmation keeping the entry unconfirmed.
3. Second clone now wants to commit labels and adds the new extension
for that breaking the pointer in the expectation list causing
UAF on the destruction path later.
While this is possible to trigger, there should be no practical
network pipeline where committing both clones without modifications
into the same zone is needed. So, let's just reset the entry in case
for some reason we got an skb with a shared one during commit. This
doesn't affect any known use cases, but avoids any potential problems
with sharing and modification of the unconfirmed ct entry.
The fixes tag points to the introduction of helpers, since that's the
main UAF trigger for the sharing. |
| In the Linux kernel, the following vulnerability has been resolved:
net: openvswitch: conntrack: fix helper UAF due to extensions realloc
While calling the helpers, a raw pointer to the extensions area is
wired into expectations list:
-> nf_ct_helper()
-> helper->help()
-> nf_ct_expect_related_report()
-> nf_ct_expect_insert()
-> hlist_add_head_rcu(&exp->lnode, &master_help->expectations)
In case the connection is not confirmed yet, more extensions can be
added afterwards with *_ext_add() calls reallocating the extension
space and leaving the now invalid pointer in the expectations list
that is later accessed while removing the expectation.
Make sure that helpers are called at the end after all the other
extensions are already added.
Note that the helper rejection now leaves the mark and labels set,
but that's not different from how the NAT was handled before or how
the mark and the labels were handled on confirmation failure. And
there are no atomicity guarantees provided by the API anyway. |
| In the Linux kernel, the following vulnerability has been resolved:
net: bridge: mdb: restart port group walk after deletion
br_mdb_flush_pgs() keeps a pointer-to-pointer cursor while walking
mp->ports. br_multicast_del_pg() can re-enter the same MDB entry through
br_multicast_sg_del_exclude_ports() and unlink other port groups. If the
cursor points into one of those groups, the next iteration dereferences a
stale cursor and can leave mp->ports pointing at freed memory.
A following RTM_GETMDB exposes the dangling pointer:
BUG: KASAN: slab-use-after-free in br_mdb_dump
Read of size 8
br_mdb_dump
rtnl_mdb_dump
rtnl_dumpit
netlink_dump
Reset the cursor to mp->ports after every deletion. The deletion removes at
least the selected group, so the restarted walk always makes progress. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: ip6t_rt: fix zero-address non-strict match out-of-bounds read
rt_mt6_check() permits rules to be configured with rtinfo->addrnr == 0
even when address matching (IP6T_RT_FST_MASK) is requested.
In the IP6T_RT_FST_NSTRICT path, rt_mt6() evaluates packet routing
addresses against rtinfo->addrs[i] and terminates backwards at the bottom
of the loop:
if (ipv6_addr_equal(ap, &rtinfo->addrs[i])) {
i++;
}
if (i == rtinfo->addrnr)
break;
When addrnr is 0, if the first packet address matches rtinfo->addrs[0],
i is incremented to 1. Because i is now strictly greater than addrnr (0),
the loop termination condition (i == rtinfo->addrnr) is bypassed and will
never be satisfied.
If a crafted IPv6 packet contains matching routing addresses, i will
advance past IP6T_RT_HOPS (16). The subsequent call to ipv6_addr_equal()
reads beyond struct ip6t_rt, triggering UBSAN/KASAN out-of-bounds warnings
or kernel panics.
Fix this by:
1. Rejecting rules in rt_mt6_check() where IP6T_RT_FST_MASK is set but
rtinfo->addrnr is zero.
2. In rt_mt6(), moving the termination condition (i < rtinfo->addrnr)
into the for-loop header condition and removing the backwards break
at the end of the loop body. |
