| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
e1000: fix OOB in e1000_tbi_should_accept()
In e1000_tbi_should_accept() we read the last byte of the frame via
'data[length - 1]' to evaluate the TBI workaround. If the descriptor-
reported length is zero or larger than the actual RX buffer size, this
read goes out of bounds and can hit unrelated slab objects. The issue
is observed from the NAPI receive path (e1000_clean_rx_irq):
==================================================================
BUG: KASAN: slab-out-of-bounds in e1000_tbi_should_accept+0x610/0x790
Read of size 1 at addr ffff888014114e54 by task sshd/363
CPU: 0 PID: 363 Comm: sshd Not tainted 5.18.0-rc1 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
<IRQ>
dump_stack_lvl+0x5a/0x74
print_address_description+0x7b/0x440
print_report+0x101/0x200
kasan_report+0xc1/0xf0
e1000_tbi_should_accept+0x610/0x790
e1000_clean_rx_irq+0xa8c/0x1110
e1000_clean+0xde2/0x3c10
__napi_poll+0x98/0x380
net_rx_action+0x491/0xa20
__do_softirq+0x2c9/0x61d
do_softirq+0xd1/0x120
</IRQ>
<TASK>
__local_bh_enable_ip+0xfe/0x130
ip_finish_output2+0x7d5/0xb00
__ip_queue_xmit+0xe24/0x1ab0
__tcp_transmit_skb+0x1bcb/0x3340
tcp_write_xmit+0x175d/0x6bd0
__tcp_push_pending_frames+0x7b/0x280
tcp_sendmsg_locked+0x2e4f/0x32d0
tcp_sendmsg+0x24/0x40
sock_write_iter+0x322/0x430
vfs_write+0x56c/0xa60
ksys_write+0xd1/0x190
do_syscall_64+0x43/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f511b476b10
Code: 73 01 c3 48 8b 0d 88 d3 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d f9 2b 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 8e 9b 01 00 48 89 04 24
RSP: 002b:00007ffc9211d4e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000004024 RCX: 00007f511b476b10
RDX: 0000000000004024 RSI: 0000559a9385962c RDI: 0000000000000003
RBP: 0000559a9383a400 R08: fffffffffffffff0 R09: 0000000000004f00
R10: 0000000000000070 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc9211d57f R14: 0000559a9347bde7 R15: 0000000000000003
</TASK>
Allocated by task 1:
__kasan_krealloc+0x131/0x1c0
krealloc+0x90/0xc0
add_sysfs_param+0xcb/0x8a0
kernel_add_sysfs_param+0x81/0xd4
param_sysfs_builtin+0x138/0x1a6
param_sysfs_init+0x57/0x5b
do_one_initcall+0x104/0x250
do_initcall_level+0x102/0x132
do_initcalls+0x46/0x74
kernel_init_freeable+0x28f/0x393
kernel_init+0x14/0x1a0
ret_from_fork+0x22/0x30
The buggy address belongs to the object at ffff888014114000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1620 bytes to the right of
2048-byte region [ffff888014114000, ffff888014114800]
The buggy address belongs to the physical page:
page:ffffea0000504400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14110
head:ffffea0000504400 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x100000000010200(slab|head|node=0|zone=1)
raw: 0100000000010200 0000000000000000 dead000000000001 ffff888013442000
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
==================================================================
This happens because the TBI check unconditionally dereferences the last
byte without validating the reported length first:
u8 last_byte = *(data + length - 1);
Fix by rejecting the frame early if the length is zero, or if it exceeds
adapter->rx_buffer_len. This preserves the TBI workaround semantics for
valid frames and prevents touching memory beyond the RX buffer. |
| In the Linux kernel, the following vulnerability has been resolved:
f2fs: invalidate dentry cache on failed whiteout creation
F2FS can mount filesystems with corrupted directory depth values that
get runtime-clamped to MAX_DIR_HASH_DEPTH. When RENAME_WHITEOUT
operations are performed on such directories, f2fs_rename performs
directory modifications (updating target entry and deleting source
entry) before attempting to add the whiteout entry via f2fs_add_link.
If f2fs_add_link fails due to the corrupted directory structure, the
function returns an error to VFS, but the partial directory
modifications have already been committed to disk. VFS assumes the
entire rename operation failed and does not update the dentry cache,
leaving stale mappings.
In the error path, VFS does not call d_move() to update the dentry
cache. This results in new_dentry still pointing to the old inode
(new_inode) which has already had its i_nlink decremented to zero.
The stale cache causes subsequent operations to incorrectly reference
the freed inode.
This causes subsequent operations to use cached dentry information that
no longer matches the on-disk state. When a second rename targets the
same entry, VFS attempts to decrement i_nlink on the stale inode, which
may already have i_nlink=0, triggering a WARNING in drop_nlink().
Example sequence:
1. First rename (RENAME_WHITEOUT): file2 → file1
- f2fs updates file1 entry on disk (points to inode 8)
- f2fs deletes file2 entry on disk
- f2fs_add_link(whiteout) fails (corrupted directory)
- Returns error to VFS
- VFS does not call d_move() due to error
- VFS cache still has: file1 → inode 7 (stale!)
- inode 7 has i_nlink=0 (already decremented)
2. Second rename: file3 → file1
- VFS uses stale cache: file1 → inode 7
- Tries to drop_nlink on inode 7 (i_nlink already 0)
- WARNING in drop_nlink()
Fix this by explicitly invalidating old_dentry and new_dentry when
f2fs_add_link fails during whiteout creation. This forces VFS to
refresh from disk on subsequent operations, ensuring cache consistency
even when the rename partially succeeds.
Reproducer:
1. Mount F2FS image with corrupted i_current_depth
2. renameat2(file2, file1, RENAME_WHITEOUT)
3. renameat2(file3, file1, 0)
4. System triggers WARNING in drop_nlink() |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/bnxt_re: Fix OOB write in bnxt_re_copy_err_stats()
Commit ef56081d1864 ("RDMA/bnxt_re: RoCE related hardware counters
update") added three new counters and placed them after
BNXT_RE_OUT_OF_SEQ_ERR.
BNXT_RE_OUT_OF_SEQ_ERR acts as a boundary marker for allocating hardware
statistics with different num_counters values on chip_gen_p5_p7 devices.
As a result, BNXT_RE_NUM_STD_COUNTERS are used when allocating
hw_stats, which leads to an out-of-bounds write in
bnxt_re_copy_err_stats().
The counters BNXT_RE_REQ_CQE_ERROR, BNXT_RE_RESP_CQE_ERROR, and
BNXT_RE_RESP_REMOTE_ACCESS_ERRS are applicable to generic hardware, not
only p5/p7 devices.
Fix this by moving these counters before BNXT_RE_OUT_OF_SEQ_ERR so they
are included in the generic counter set. |
| In the Linux kernel, the following vulnerability has been resolved:
net: hns3: using the num_tqps in the vf driver to apply for resources
Currently, hdev->htqp is allocated using hdev->num_tqps, and kinfo->tqp
is allocated using kinfo->num_tqps. However, kinfo->num_tqps is set to
min(new_tqps, hdev->num_tqps); Therefore, kinfo->num_tqps may be smaller
than hdev->num_tqps, which causes some hdev->htqp[i] to remain
uninitialized in hclgevf_knic_setup().
Thus, this patch allocates hdev->htqp and kinfo->tqp using hdev->num_tqps,
ensuring that the lengths of hdev->htqp and kinfo->tqp are consistent
and that all elements are properly initialized. |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix use-after-free in ksmbd_tree_connect_put under concurrency
Under high concurrency, A tree-connection object (tcon) is freed on
a disconnect path while another path still holds a reference and later
executes *_put()/write on it. |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix kernel BUG in ocfs2_find_victim_chain
syzbot reported a kernel BUG in ocfs2_find_victim_chain() because the
`cl_next_free_rec` field of the allocation chain list (next free slot in
the chain list) is 0, triggring the BUG_ON(!cl->cl_next_free_rec)
condition in ocfs2_find_victim_chain() and panicking the kernel.
To fix this, an if condition is introduced in ocfs2_claim_suballoc_bits(),
just before calling ocfs2_find_victim_chain(), the code block in it being
executed when either of the following conditions is true:
1. `cl_next_free_rec` is equal to 0, indicating that there are no free
chains in the allocation chain list
2. `cl_next_free_rec` is greater than `cl_count` (the total number of
chains in the allocation chain list)
Either of them being true is indicative of the fact that there are no
chains left for usage.
This is addressed using ocfs2_error(), which prints
the error log for debugging purposes, rather than panicking the kernel. |
| In the Linux kernel, the following vulnerability has been resolved:
svcrdma: use rc_pageoff for memcpy byte offset
svc_rdma_copy_inline_range added rc_curpage (page index) to the page
base instead of the byte offset rc_pageoff. Use rc_pageoff so copies
land within the current page.
Found by ZeroPath (https://zeropath.com) |
| In the Linux kernel, the following vulnerability has been resolved:
caif: fix integer underflow in cffrml_receive()
The cffrml_receive() function extracts a length field from the packet
header and, when FCS is disabled, subtracts 2 from this length without
validating that len >= 2.
If an attacker sends a malicious packet with a length field of 0 or 1
to an interface with FCS disabled, the subtraction causes an integer
underflow.
This can lead to memory exhaustion and kernel instability, potential
information disclosure if padding contains uninitialized kernel memory.
Fix this by validating that len >= 2 before performing the subtraction. |
| In the Linux kernel, the following vulnerability has been resolved:
hwmon: (ibmpex) fix use-after-free in high/low store
The ibmpex_high_low_store() function retrieves driver data using
dev_get_drvdata() and uses it without validation. This creates a race
condition where the sysfs callback can be invoked after the data
structure is freed, leading to use-after-free.
Fix by adding a NULL check after dev_get_drvdata(), and reordering
operations in the deletion path to prevent TOCTOU. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv4: Fix reference count leak when using error routes with nexthop objects
When a nexthop object is deleted, it is marked as dead and then
fib_table_flush() is called to flush all the routes that are using the
dead nexthop.
The current logic in fib_table_flush() is to only flush error routes
(e.g., blackhole) when it is called as part of network namespace
dismantle (i.e., with flush_all=true). Therefore, error routes are not
flushed when their nexthop object is deleted:
# ip link add name dummy1 up type dummy
# ip nexthop add id 1 dev dummy1
# ip route add 198.51.100.1/32 nhid 1
# ip route add blackhole 198.51.100.2/32 nhid 1
# ip nexthop del id 1
# ip route show
blackhole 198.51.100.2 nhid 1 dev dummy1
As such, they keep holding a reference on the nexthop object which in
turn holds a reference on the nexthop device, resulting in a reference
count leak:
# ip link del dev dummy1
[ 70.516258] unregister_netdevice: waiting for dummy1 to become free. Usage count = 2
Fix by flushing error routes when their nexthop is marked as dead.
IPv6 does not suffer from this problem. |
| In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: fix the crash issue for zero copy XDP_TX action
There is a crash issue when running zero copy XDP_TX action, the crash
log is shown below.
[ 216.122464] Unable to handle kernel paging request at virtual address fffeffff80000000
[ 216.187524] Internal error: Oops: 0000000096000144 [#1] SMP
[ 216.301694] Call trace:
[ 216.304130] dcache_clean_poc+0x20/0x38 (P)
[ 216.308308] __dma_sync_single_for_device+0x1bc/0x1e0
[ 216.313351] stmmac_xdp_xmit_xdpf+0x354/0x400
[ 216.317701] __stmmac_xdp_run_prog+0x164/0x368
[ 216.322139] stmmac_napi_poll_rxtx+0xba8/0xf00
[ 216.326576] __napi_poll+0x40/0x218
[ 216.408054] Kernel panic - not syncing: Oops: Fatal exception in interrupt
For XDP_TX action, the xdp_buff is converted to xdp_frame by
xdp_convert_buff_to_frame(). The memory type of the resulting xdp_frame
depends on the memory type of the xdp_buff. For page pool based xdp_buff
it produces xdp_frame with memory type MEM_TYPE_PAGE_POOL. For zero copy
XSK pool based xdp_buff it produces xdp_frame with memory type
MEM_TYPE_PAGE_ORDER0. However, stmmac_xdp_xmit_back() does not check the
memory type and always uses the page pool type, this leads to invalid
mappings and causes the crash. Therefore, check the xdp_buff memory type
in stmmac_xdp_xmit_back() to fix this issue. |
| In the Linux kernel, the following vulnerability has been resolved:
net: usb: asix: validate PHY address before use
The ASIX driver reads the PHY address from the USB device via
asix_read_phy_addr(). A malicious or faulty device can return an
invalid address (>= PHY_MAX_ADDR), which causes a warning in
mdiobus_get_phy():
addr 207 out of range
WARNING: drivers/net/phy/mdio_bus.c:76
Validate the PHY address in asix_read_phy_addr() and remove the
now-redundant check in ax88172a.c. |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix nfsd_file reference leak in nfsd4_add_rdaccess_to_wrdeleg()
nfsd4_add_rdaccess_to_wrdeleg() unconditionally overwrites
fp->fi_fds[O_RDONLY] with a newly acquired nfsd_file. However, if
the client already has a SHARE_ACCESS_READ open from a previous OPEN
operation, this action overwrites the existing pointer without
releasing its reference, orphaning the previous reference.
Additionally, the function originally stored the same nfsd_file
pointer in both fp->fi_fds[O_RDONLY] and fp->fi_rdeleg_file with
only a single reference. When put_deleg_file() runs, it clears
fi_rdeleg_file and calls nfs4_file_put_access() to release the file.
However, nfs4_file_put_access() only releases fi_fds[O_RDONLY] when
the fi_access[O_RDONLY] counter drops to zero. If another READ open
exists on the file, the counter remains elevated and the nfsd_file
reference from the delegation is never released. This potentially
causes open conflicts on that file.
Then, on server shutdown, these leaks cause __nfsd_file_cache_purge()
to encounter files with an elevated reference count that cannot be
cleaned up, ultimately triggering a BUG() in kmem_cache_destroy()
because there are still nfsd_file objects allocated in that cache. |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: fallback earlier on simult connection
Syzkaller reports a simult-connect race leading to inconsistent fallback
status:
WARNING: CPU: 3 PID: 33 at net/mptcp/subflow.c:1515 subflow_data_ready+0x40b/0x7c0 net/mptcp/subflow.c:1515
Modules linked in:
CPU: 3 UID: 0 PID: 33 Comm: ksoftirqd/3 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:subflow_data_ready+0x40b/0x7c0 net/mptcp/subflow.c:1515
Code: 89 ee e8 78 61 3c f6 40 84 ed 75 21 e8 8e 66 3c f6 44 89 fe bf 07 00 00 00 e8 c1 61 3c f6 41 83 ff 07 74 09 e8 76 66 3c f6 90 <0f> 0b 90 e8 6d 66 3c f6 48 89 df e8 e5 ad ff ff 31 ff 89 c5 89 c6
RSP: 0018:ffffc900006cf338 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888031acd100 RCX: ffffffff8b7f2abf
RDX: ffff88801e6ea440 RSI: ffffffff8b7f2aca RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000007
R10: 0000000000000004 R11: 0000000000002c10 R12: ffff88802ba69900
R13: 1ffff920000d9e67 R14: ffff888046f81800 R15: 0000000000000004
FS: 0000000000000000(0000) GS:ffff8880d69bc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000560fc0ca1670 CR3: 0000000032c3a000 CR4: 0000000000352ef0
Call Trace:
<TASK>
tcp_data_queue+0x13b0/0x4f90 net/ipv4/tcp_input.c:5197
tcp_rcv_state_process+0xfdf/0x4ec0 net/ipv4/tcp_input.c:6922
tcp_v6_do_rcv+0x492/0x1740 net/ipv6/tcp_ipv6.c:1672
tcp_v6_rcv+0x2976/0x41e0 net/ipv6/tcp_ipv6.c:1918
ip6_protocol_deliver_rcu+0x188/0x1520 net/ipv6/ip6_input.c:438
ip6_input_finish+0x1e4/0x4b0 net/ipv6/ip6_input.c:489
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
ip6_input+0x105/0x2f0 net/ipv6/ip6_input.c:500
dst_input include/net/dst.h:471 [inline]
ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
ipv6_rcv+0x264/0x650 net/ipv6/ip6_input.c:311
__netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:5979
__netif_receive_skb+0x1d/0x160 net/core/dev.c:6092
process_backlog+0x442/0x15e0 net/core/dev.c:6444
__napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7494
napi_poll net/core/dev.c:7557 [inline]
net_rx_action+0xa9f/0xfe0 net/core/dev.c:7684
handle_softirqs+0x216/0x8e0 kernel/softirq.c:579
run_ksoftirqd kernel/softirq.c:968 [inline]
run_ksoftirqd+0x3a/0x60 kernel/softirq.c:960
smpboot_thread_fn+0x3f7/0xae0 kernel/smpboot.c:160
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
The TCP subflow can process the simult-connect syn-ack packet after
transitioning to TCP_FIN1 state, bypassing the MPTCP fallback check,
as the sk_state_change() callback is not invoked for * -> FIN_WAIT1
transitions.
That will move the msk socket to an inconsistent status and the next
incoming data will hit the reported splat.
Close the race moving the simult-fallback check at the earliest possible
stage - that is at syn-ack generation time.
About the fixes tags: [2] was supposed to also fix this issue introduced
by [3]. [1] is required as a dependence: it was not explicitly marked as
a fix, but it is one and it has already been backported before [3]. In
other words, this commit should be backported up to [3], including [2]
and [1] if that's not already there. |
| In the Linux kernel, the following vulnerability has been resolved:
net: rose: fix invalid array index in rose_kill_by_device()
rose_kill_by_device() collects sockets into a local array[] and then
iterates over them to disconnect sockets bound to a device being brought
down.
The loop mistakenly indexes array[cnt] instead of array[i]. For cnt <
ARRAY_SIZE(array), this reads an uninitialized entry; for cnt ==
ARRAY_SIZE(array), it is an out-of-bounds read. Either case can lead to
an invalid socket pointer dereference and also leaks references taken
via sock_hold().
Fix the index to use i. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: BUG() in pskb_expand_head() as part of calipso_skbuff_setattr()
There exists a kernel oops caused by a BUG_ON(nhead < 0) at
net/core/skbuff.c:2232 in pskb_expand_head().
This bug is triggered as part of the calipso_skbuff_setattr()
routine when skb_cow() is passed headroom > INT_MAX
(i.e. (int)(skb_headroom(skb) + len_delta) < 0).
The root cause of the bug is due to an implicit integer cast in
__skb_cow(). The check (headroom > skb_headroom(skb)) is meant to ensure
that delta = headroom - skb_headroom(skb) is never negative, otherwise
we will trigger a BUG_ON in pskb_expand_head(). However, if
headroom > INT_MAX and delta <= -NET_SKB_PAD, the check passes, delta
becomes negative, and pskb_expand_head() is passed a negative value for
nhead.
Fix the trigger condition in calipso_skbuff_setattr(). Avoid passing
"negative" headroom sizes to skb_cow() within calipso_skbuff_setattr()
by only using skb_cow() to grow headroom.
PoC:
Using `netlabelctl` tool:
netlabelctl map del default
netlabelctl calipso add pass doi:7
netlabelctl map add default address:0::1/128 protocol:calipso,7
Then run the following PoC:
int fd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
// setup msghdr
int cmsg_size = 2;
int cmsg_len = 0x60;
struct msghdr msg;
struct sockaddr_in6 dest_addr;
struct cmsghdr * cmsg = (struct cmsghdr *) calloc(1,
sizeof(struct cmsghdr) + cmsg_len);
msg.msg_name = &dest_addr;
msg.msg_namelen = sizeof(dest_addr);
msg.msg_iov = NULL;
msg.msg_iovlen = 0;
msg.msg_control = cmsg;
msg.msg_controllen = cmsg_len;
msg.msg_flags = 0;
// setup sockaddr
dest_addr.sin6_family = AF_INET6;
dest_addr.sin6_port = htons(31337);
dest_addr.sin6_flowinfo = htonl(31337);
dest_addr.sin6_addr = in6addr_loopback;
dest_addr.sin6_scope_id = 31337;
// setup cmsghdr
cmsg->cmsg_len = cmsg_len;
cmsg->cmsg_level = IPPROTO_IPV6;
cmsg->cmsg_type = IPV6_HOPOPTS;
char * hop_hdr = (char *)cmsg + sizeof(struct cmsghdr);
hop_hdr[1] = 0x9; //set hop size - (0x9 + 1) * 8 = 80
sendmsg(fd, &msg, 0); |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: stm32: sai: fix OF node leak on probe
The reference taken to the sync provider OF node when probing the
platform device is currently only dropped if the set_sync() callback
fails during DAI probe.
Make sure to drop the reference on platform probe failures (e.g. probe
deferral) and on driver unbind.
This also avoids a potential use-after-free in case the DAI is ever
reprobed without first rebinding the platform driver. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/oa: Limit num_syncs to prevent oversized allocations
The OA open parameters did not validate num_syncs, allowing
userspace to pass arbitrarily large values, potentially
leading to excessive allocations.
Add check to ensure that num_syncs does not exceed DRM_XE_MAX_SYNCS,
returning -EINVAL when the limit is violated.
v2: use XE_IOCTL_DBG() and drop duplicated check. (Ashutosh)
(cherry picked from commit e057b2d2b8d815df3858a87dffafa2af37e5945b) |
| In the Linux kernel, the following vulnerability has been resolved:
Input: lkkbd - disable pending work before freeing device
lkkbd_interrupt() schedules lk->tq via schedule_work(), and the work
handler lkkbd_reinit() dereferences the lkkbd structure and its
serio/input_dev fields.
lkkbd_disconnect() and error paths in lkkbd_connect() free the lkkbd
structure without preventing the reinit work from being queued again
until serio_close() returns. This can allow the work handler to run
after the structure has been freed, leading to a potential use-after-free.
Use disable_work_sync() instead of cancel_work_sync() to ensure the
reinit work cannot be re-queued, and call it both in lkkbd_disconnect()
and in lkkbd_connect() error paths after serio_open(). |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: ets: Always remove class from active list before deleting in ets_qdisc_change
zdi-disclosures@trendmicro.com says:
The vulnerability is a race condition between `ets_qdisc_dequeue` and
`ets_qdisc_change`. It leads to UAF on `struct Qdisc` object.
Attacker requires the capability to create new user and network namespace
in order to trigger the bug.
See my additional commentary at the end of the analysis.
Analysis:
static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
...
// (1) this lock is preventing .change handler (`ets_qdisc_change`)
//to race with .dequeue handler (`ets_qdisc_dequeue`)
sch_tree_lock(sch);
for (i = nbands; i < oldbands; i++) {
if (i >= q->nstrict && q->classes[i].qdisc->q.qlen)
list_del_init(&q->classes[i].alist);
qdisc_purge_queue(q->classes[i].qdisc);
}
WRITE_ONCE(q->nbands, nbands);
for (i = nstrict; i < q->nstrict; i++) {
if (q->classes[i].qdisc->q.qlen) {
// (2) the class is added to the q->active
list_add_tail(&q->classes[i].alist, &q->active);
q->classes[i].deficit = quanta[i];
}
}
WRITE_ONCE(q->nstrict, nstrict);
memcpy(q->prio2band, priomap, sizeof(priomap));
for (i = 0; i < q->nbands; i++)
WRITE_ONCE(q->classes[i].quantum, quanta[i]);
for (i = oldbands; i < q->nbands; i++) {
q->classes[i].qdisc = queues[i];
if (q->classes[i].qdisc != &noop_qdisc)
qdisc_hash_add(q->classes[i].qdisc, true);
}
// (3) the qdisc is unlocked, now dequeue can be called in parallel
// to the rest of .change handler
sch_tree_unlock(sch);
ets_offload_change(sch);
for (i = q->nbands; i < oldbands; i++) {
// (4) we're reducing the refcount for our class's qdisc and
// freeing it
qdisc_put(q->classes[i].qdisc);
// (5) If we call .dequeue between (4) and (5), we will have
// a strong UAF and we can control RIP
q->classes[i].qdisc = NULL;
WRITE_ONCE(q->classes[i].quantum, 0);
q->classes[i].deficit = 0;
gnet_stats_basic_sync_init(&q->classes[i].bstats);
memset(&q->classes[i].qstats, 0, sizeof(q->classes[i].qstats));
}
return 0;
}
Comment:
This happens because some of the classes have their qdiscs assigned to
NULL, but remain in the active list. This commit fixes this issue by always
removing the class from the active list before deleting and freeing its
associated qdisc
Reproducer Steps
(trimmed version of what was sent by zdi-disclosures@trendmicro.com)
```
DEV="${DEV:-lo}"
ROOT_HANDLE="${ROOT_HANDLE:-1:}"
BAND2_HANDLE="${BAND2_HANDLE:-20:}" # child under 1:2
PING_BYTES="${PING_BYTES:-48}"
PING_COUNT="${PING_COUNT:-200000}"
PING_DST="${PING_DST:-127.0.0.1}"
SLOW_TBF_RATE="${SLOW_TBF_RATE:-8bit}"
SLOW_TBF_BURST="${SLOW_TBF_BURST:-100b}"
SLOW_TBF_LAT="${SLOW_TBF_LAT:-1s}"
cleanup() {
tc qdisc del dev "$DEV" root 2>/dev/null
}
trap cleanup EXIT
ip link set "$DEV" up
tc qdisc del dev "$DEV" root 2>/dev/null || true
tc qdisc add dev "$DEV" root handle "$ROOT_HANDLE" ets bands 2 strict 2
tc qdisc add dev "$DEV" parent 1:2 handle "$BAND2_HANDLE" \
tbf rate "$SLOW_TBF_RATE" burst "$SLOW_TBF_BURST" latency "$SLOW_TBF_LAT"
tc filter add dev "$DEV" parent 1: protocol all prio 1 u32 match u32 0 0 flowid 1:2
tc -s qdisc ls dev $DEV
ping -I "$DEV" -f -c "$PING_COUNT" -s "$PING_BYTES" -W 0.001 "$PING_DST" \
>/dev/null 2>&1 &
tc qdisc change dev "$DEV" root handle "$ROOT_HANDLE" ets bands 2 strict 0
tc qdisc change dev "$DEV" root handle "$ROOT_HANDLE" ets bands 2 strict 2
tc -s qdisc ls dev $DEV
tc qdisc del dev "$DEV" parent
---truncated--- |
