| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
pppoe: reload header pointer after dev_hard_header()
pppoe_sendmsg() saves a pointer to the PPPoE header before calling
dev_hard_header(). Device header callbacks are allowed to reallocate the
skb head, invalidating pointers into it.
This can happen when a send is blocked in copy_from_user() while the first
non-Ethernet port is added to an empty team device. The team's delegated
GRE header callback then expands the skb head. PPPoE subsequently writes
six bytes through the stale pointer into the freed head.
Reload the PPPoE header through the skb's network-header offset after
device header creation. pskb_expand_head() updates that offset when it
relocates the head. |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: clear sock->sk on the failed-insert path in tipc_sk_create()
When tipc_sk_create() fails to insert the new socket (tipc_sk_insert()
returns non-zero), its error path frees the sk with sk_free() but leaves
sock->sk pointing at the freed object:
if (tipc_sk_insert(tsk)) {
sk_free(sk);
pr_warn("Socket create failed; port number exhausted\n");
return -EINVAL;
}
This is harmless for plain socket(): the syscall layer clears sock->ops
before releasing, so tipc_release() is never called. It is not harmless
on the accept() path. tipc_accept() creates the pre-allocated child
socket with tipc_sk_create(net, new_sock, 0, kern); on failure it leaves
new_sock->sk dangling and new_sock->ops non-NULL, and do_accept() then
fput()s the new file, so __sock_release() -> tipc_release() runs
lock_sock(new_sock->sk) on the freed sk -- a use-after-free write of the
sk_lock spinlock.
tipc_release() already guards this exact "failed accept() releases a
pre-allocated child" case with "if (sk == NULL) return 0;", but the
guard is bypassed because tipc_sk_create() left sock->sk non-NULL
(dangling) rather than NULL.
Clear sock->sk on the failed-insert path so the existing tipc_release()
NULL check fires and the use-after-free is avoided.
The tipc_sk_insert() failure is reached when the per-netns socket
rhashtable hits its max_size (tsk_rht_params.max_size = 1048576, ~2M
elements) -- i.e. once a netns holds ~2M TIPC sockets every insert
returns -E2BIG.
BUG: KASAN: slab-use-after-free in lock_sock_nested (net/core/sock.c:3839)
Write of size 8 at addr ffff8880047cdc38 by task init/1
lock_sock_nested (net/core/sock.c:3839)
tipc_release (net/tipc/socket.c:638)
__sock_release (net/socket.c:710)
sock_close (net/socket.c:1501)
__fput (fs/file_table.c:512)
Allocated by task 1:
sk_alloc (net/core/sock.c:2308)
tipc_sk_create (net/tipc/socket.c:487)
tipc_accept (net/tipc/socket.c:2744)
do_accept (net/socket.c:2034)
Freed by task 1:
__sk_destruct (net/core/sock.c:2391)
tipc_sk_create (net/tipc/socket.c:504)
tipc_accept (net/tipc/socket.c:2744)
do_accept (net/socket.c:2034) |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: invoke pm_genpd_remove() before freeing genpd
Call pm_genpd_remove() to unregister from global list prior to releasing
acp_genpd memory, and clear the pointer after free.
(cherry picked from commit cd8650d7a91ee8b768e202354672553faa5cc1f2) |
| In the Linux kernel, the following vulnerability has been resolved:
audit: fix recursive locking deadlock in audit_dupe_exe()
A deadlock occurs in the audit subsystem when duplicating
executable-related rules.
When a file is moved (e.g., via do_renameat2()), the VFS layer locks
the parent directory (I_MUTEX_PARENT), which synchronously triggers an
fsnotify_move event. If an existing executable audit rule matches the
file being moved, the audit subsystem catches this event and calls
audit_dupe_exe() to duplicate the watch and update the rule. Then,
audit_alloc_mark() would call kern_path_parent() to resolve the path,
leading to a blind attempt to acquire the exact same I_MUTEX_PARENT lock
already held by the task, resulting in the following recursive locking
deadlock:
============================================
WARNING: possible recursive locking detected
6.12.0-55.27.1.el10_0.x86_64+debug #1 Not tainted
--------------------------------------------
mv/5099 is trying to acquire lock:
ffff888132845358 (&inode->i_sb->s_type->i_mutex_dir_key/1){+.+.}-{3:3},
at: __kern_path_locked+0x10a/0x2f0
but task is already holding lock:
ffff888132846b58 (&inode->i_sb->s_type->i_mutex_dir_key/1){+.+.}-{3:3},
at: lock_two_directories+0x13f/0x2b0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&inode->i_sb->s_type->i_mutex_dir_key/1);
lock(&inode->i_sb->s_type->i_mutex_dir_key/1);
*** DEADLOCK ***
May be due to missing lock nesting notation
6 locks held by mv/5099:
#0: ffff888112a9c440 (sb_writers#13)
at: do_renameat2+0x34c/0xbc0
#1: ffff888112a9c790 (&type->s_vfs_rename_key#3)
at: do_renameat2+0x415/0xbc0
#2: ffff888132846b58 (&inode->i_sb->s_type->i_mutex_dir_key/1)
at: lock_two_directories+0x13f/0x2b0
#3: ffff888132845358 (&inode->i_sb->s_type->i_mutex_dir_key/5)
at: lock_two_directories+0x175/0x2b0
#4: ffffffffb3a1fb10 (&fsnotify_mark_srcu)
at: fsnotify+0x454/0x28a0
#5: ffffffffaf886230 (audit_filter_mutex)
at: audit_update_watch+0x36/0x11e0
stack backtrace:
Call Trace:
<TASK>
dump_stack_lvl+0x6f/0xb0
print_deadlock_bug.cold+0xbd/0xca
validate_chain+0x83a/0xf00
__lock_acquire+0xcac/0x1d20
lock_acquire.part.0+0x11b/0x360
down_write_nested+0x9f/0x230
__kern_path_locked+0x10a/0x2f0
kern_path_locked+0x26/0x40
audit_alloc_mark+0xfb/0x4f0
audit_dupe_exe+0x6c/0xe0
audit_dupe_rule+0x6c2/0xc00
audit_update_watch+0x4cc/0x11e0
audit_watch_handle_event+0x12c/0x1b0
send_to_group+0x5d0/0x8b0
fsnotify+0x615/0x28a0
fsnotify_move+0x1d8/0x630
vfs_rename+0xdcd/0x1df0
do_renameat2+0x9d4/0xbc0
__x64_sys_renameat+0x192/0x260
do_syscall_64+0x92/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f0491fe8c4e
Code: 0f 1f 40 00 48 8b 15 c1 e1 16 00 f7 d8 64 89 02 b8 ff ff ff ff
c3 66 0f 1f 44 00 00 f3 0f 1e fa 49 89 ca b8 08 01 00 00 0f 05 <48>
3d 00 f0 ff ff 77 0a c3 66 0f 1f 84 00 00 00 00 00 48 8b 15 89
RSP: 002b:00007ffc7210bf38 EFLAGS: 00000246 ORIG_RAX: 0000000000000108
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0491fe8c4e
RDX: 0000000000000003 RSI: 00007ffc7210e6c8 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: 00005575eb2dae2a R11: 0000000000000246 R12: 00005575eb2dae2a
R13: 00007ffc7210e6c8 R14: 0000000000000003 R15: 00000000ffffff9c
</TASK>
The aforementioned deadlock can be consistently reproduced by running
the script below:
audit-dupe-exe-deadlock.sh
--------------------------
#!/bin/bash
auditctl -D
mkdir -p /tmp/foo
touch /tmp/file
auditctl -a always,exit -F exe=/tmp/file -F path=/tmp/file -S all -k dr
mv /tmp/file /tmp/foo/file
rm -Rf /tmp/foo
This patch fixes the issue by introducing struct audit_watch_ctx to pass
the fsnotify event context down to audit_alloc_mark(). By utilizing the
already-resolved directory inode provided by the event, we bypass the
kern_path_parent() path resol
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: Fix a use-after-free problem in rxe_mmap
rxe_mmap() removes a rxe_mmap_info struct from the pending_mmaps list
and releases pending_lock while the struct's kref is still at 1:
list_del_init(&ip->pending_mmaps);
spin_unlock_bh(&rxe->pending_lock); /* ref == 1, no lock held */
ret = remap_vmalloc_range(vma, ip->obj, 0); /* walks PTEs */
[...]
rxe_vma_open(vma); /* kref_get, ref → 2 */
remap_vmalloc_range_partial() walks PTEs without any lock.
A concurrent DESTROY_CQ ioctl on another CPU calls:
kref_put(&q->ip->ref, rxe_mmap_release) /* ref 1→0 */
vfree(ip->obj) /* clears vmalloc PTEs mid-walk */
kfree(ip) /* frees rxe_mmap_info */
This yields:
1. Kernel crash, vmalloc_to_page() returns NULL when vfree wins the
per-PTE race -> vm_insert_page(NULL) → GPF in validate_page_before_insert
2. Page UAF, vmalloc_to_page() reads a stale PTE before vfree clears
it. User VMA holds a PTE to a free'd page which might eventually get
reallocated later by vmalloc which allows the attacker to get a clean
page-level UAF.
It is worth noting that even though a page-level UAF is possible given
the strong primitive, it is statistically very difficult to achieve
given the very short time window (after the last insert_page and before
the kref_get).
The call trace are as below:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 UID: 1000 PID: 413 Comm: poc Not tainted 7.0.0-rc5-dirty #28 PREEMPT(lazy)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:validate_page_before_insert+0x32/0x300
Code: e5 41 57 41 56 49 89 fe 41 55 41 54 53 48 89 f3 e8 93 b5 a3 ff 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 7b 02 00 00 4c 8b 63 08 31 ff 4d 89 e5 41 83 e5
RSP: 0018:ffff88811b15f2f0 EFLAGS: 00000202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000008
RBP: ffff88811b15f318 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881181eee00
R13: 0000000000000000 R14: ffff8881181eee00 R15: ffff8881181eee20
FS: 00007b1e000f76c0(0000) GS:ffff8884268e0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007b1e00a24ac0 CR3: 0000000116eb3000 CR4: 00000000000006f0
Call Trace:
<TASK>
insert_page+0x8f/0x190
? __pfx_insert_page+0x10/0x10
? kasan_save_alloc_info+0x38/0x60
vm_insert_page+0x2e7/0x400
remap_vmalloc_range_partial+0x212/0x3e0
remap_vmalloc_range+0x6e/0xb0
? __kasan_check_write+0x14/0x30
rxe_mmap+0x2e9/0x5d0
ib_uverbs_mmap+0x1ad/0x2c0
__mmap_region+0x12c2/0x2ad0
? __pfx___mmap_region+0x10/0x10
? __sanitizer_cov_trace_switch+0x58/0xb0
? mas_prev_slot+0x360/0x39c0
? __sanitizer_cov_trace_switch+0x58/0xb0
? mas_next_slot+0x1e5b/0x2f40
? __sanitizer_cov_trace_cmp8+0x18/0x30
? unmapped_area_topdown+0x4dd/0x610
? kfree+0x1b1/0x440
? free_cpumask_var+0x16/0x30
? __kasan_slab_free+0x7d/0xa0
? __sanitizer_cov_trace_cmp8+0x18/0x30
mmap_region+0x2e6/0x3c0
do_mmap+0xa3e/0x12a0
? __pfx_do_mmap+0x10/0x10
? __kasan_check_write+0x14/0x30
? down_write_killable+0xba/0x160
? __pfx_down_write_killable+0x10/0x10
? __sanitizer_cov_trace_cmp4+0x16/0x30
vm_mmap_pgoff+0x2d4/0x4a0
? __pfx_vm_mmap_pgoff+0x10/0x10
? fget+0x1bf/0x270
ksys_mmap_pgoff+0x40c/0x690
? __sanitizer_cov_trace_const_cmp4+0x16/0x30
? __pfx_ksys_mmap_pgoff+0x10/0x10
? __kasan_check_write+0x14/0x30
? _raw_spin_trylock+0xbb/0x130
? __pfx__raw_spin_trylock+0x10/0x10
__x64_sys_mmap+0x135/0x1e0
x64_sys_c
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
nexthop: initialize extack in nh_res_bucket_migrate()
nh_res_bucket_migrate() passes an uninitialized netlink_ext_ack to
call_nexthop_res_bucket_notifiers(). When
nh_notifier_res_bucket_info_init() fails (e.g. the kzalloc returns
-ENOMEM), the error is propagated back before any notifier sets
extack._msg, and the error path formats the stale pointer with
pr_err_ratelimited("%s\n", extack._msg). With CONFIG_INIT_STACK_NONE
this dereferences uninitialized stack memory:
Oops: general protection fault, probably for non-canonical address ...
KASAN: maybe wild-memory-access in range [...]
RIP: 0010:string (lib/vsprintf.c:730)
vsnprintf (lib/vsprintf.c:2945)
_printk (kernel/printk/printk.c:2504)
nh_res_bucket_migrate (net/ipv4/nexthop.c:1816)
nh_res_table_upkeep (net/ipv4/nexthop.c:1866)
rtm_new_nexthop (net/ipv4/nexthop.c:3323)
rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)
netlink_sendmsg (net/netlink/af_netlink.c:1900)
Kernel panic - not syncing: Fatal exception
Zero-initialize extack so _msg is NULL on error paths that never set it. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: tcp: fix double sock release on batch realloc
bpf_iter_tcp_batch() releases the current batch via
bpf_iter_tcp_put_batch(), which drops the socket refs and rewrites
each slot with the socket cookie, then grows the batch. cur_sk/end_sk
are kept for bpf_iter_tcp_resume(), but on realloc failure the function
returns ERR_PTR() before resume runs, leaving cur_sk < end_sk over
slots that now hold cookies rather than sock pointers.
bpf_iter_tcp_seq_stop() then calls bpf_iter_tcp_put_batch() again and
dereferences a cookie as a struct sock.
Empty the batch on the failure path so stop() does not release it
again. The sockets were already freed by the first
bpf_iter_tcp_put_batch(), so nothing leaks, and a later read() rescans
the bucket from the start instead of skipping it. The sibling
GFP_NOWAIT failure path still holds real socket references and is left
for stop() to release.
BUG: KASAN: null-ptr-deref in __sock_gen_cookie
Read of size 8 at addr 0000000000000059 by task exploit
...
__sock_gen_cookie (net/core/sock_diag.c:28)
bpf_iter_tcp_put_batch (net/ipv4/tcp_ipv4.c:2918)
bpf_iter_tcp_seq_stop (net/ipv4/tcp_ipv4.c:3270)
bpf_seq_read (kernel/bpf/bpf_iter.c:205)
vfs_read (fs/read_write.c:572)
ksys_read (fs/read_write.c:716)
do_syscall_64
entry_SYSCALL_64_after_hwframe
Kernel panic - not syncing: Fatal exception |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: tear down new links on vif update error path
When ieee80211_vif_update_links() adds new links it allocates a link
container for each and calls ieee80211_link_init() (which registers the
per-link debugfs files with file->private_data pointing into the container)
and ieee80211_link_setup(). If the subsequent drv_change_vif_links() fails,
the error path restores the old pointers and jumps to 'free', which frees
the new containers but never removes their debugfs entries or stops the
links. The debugfs files survive with file->private_data dangling at the
freed container, so a later open()+read() (e.g. link-1/txpower)
dereferences freed memory in ieee80211_if_read_link(), a use-after-free.
The removal path already dismantles links correctly via
ieee80211_tear_down_links(), which removes each link's keys and debugfs
entries and calls ieee80211_link_stop(); the add path on the error branch
does not. Commit be1ba9ed221f ("wifi: mac80211: avoid weird state in error
path") hardened this same error path for the link-removal case
(new_links == 0) but left the newly-added links' teardown unaddressed.
drv_change_vif_links() can fail at runtime on MLO drivers (internal
allocation / queue / firmware command failures).
Remove the new links' debugfs entries and stop them before freeing.
BUG: KASAN: slab-use-after-free in ieee80211_if_read_link (net/mac80211/debugfs_netdev.c:127)
Read of size 8 at addr ffff888011290000 by task exploit/145
Call Trace:
...
ieee80211_if_read_link (net/mac80211/debugfs_netdev.c:127)
short_proxy_read (fs/debugfs/file.c:373)
vfs_read (fs/read_write.c:572)
ksys_read (fs/read_write.c:716)
do_syscall_64 (arch/x86/entry/syscall_64.c:94)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
...
Oops: general protection fault, probably for non-canonical address 0xdffffc000000000a
RIP: 0010:ieee80211_if_read_link (net/mac80211/debugfs_netdev.c:127)
Kernel panic - not syncing: Fatal exception |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: don't free the ASCONF's own transport in DEL-IP processing
sctp_process_asconf() caches the transport the ASCONF chunk is processed
against in asconf->transport (== chunk->transport, set once in sctp_rcv()).
For an ASCONF located through its Address Parameter by
__sctp_rcv_asconf_lookup(), that cached transport corresponds to the
Address Parameter, which need not be the packet's source address.
sctp_process_asconf_param() rejects a DEL-IP for the packet source address
(ADDIP D8, SCTP_ERROR_DEL_SRC_IP), but nothing protects asconf->transport.
A single ASCONF can therefore carry, in order:
[Address Parameter L] [DEL-IP L] [DEL-IP 0.0.0.0]
where L differs from the source. The DEL-IP for L passes the D8 check and
calls sctp_assoc_rm_peer() on the transport that asconf->transport still
points at, freeing it (RCU-deferred). The following wildcard DEL-IP then
reuses the now-dangling asconf->transport in sctp_assoc_set_primary() and
sctp_assoc_del_nonprimary_peers(): set_primary() dereferences the freed
transport (->ipaddr, ->state) and plants the dangling pointer into
asoc->peer.primary_path / active_path, and del_nonprimary_peers(), keeping
only the pointer that is no longer on the list, removes every real
transport, leaving the association with a transport_count of 0 and
primary_path/active_path pointing at freed memory.
Reject a DEL-IP that targets the transport the ASCONF is being processed
against, mirroring the existing source-address guard, so the wildcard
branch can never reuse a freed transport. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Check for invalid/obsolete root *after* making MMU pages available
Check for a "stale" page fault, i.e. for an invalid and/or obsolete root,
after making MMU pages available for the shadow MMU. If reclaiming shadow
pages zaps an in-use root, i.e. marks it invalid, then KVM will attempt to
map memory into an invalid root. On its own, populating an invalid root is
"fine", but because child shadow pages inherit their parent's role, any
children created during the map/fetch will be created as invalid pages,
thus violating KVM's invariant that invalid pages are never on the list of
active MMU pages.
Note, the underlying flaw has existed since KVM first started tracking
invalid roots in 2008 (commit 2e53d63acba7, "KVM: MMU: ignore zapped root
pagetables"), but the true badness only came along in 2020 (Linux 5.9)
with the invariant that invalid shadow pages can't be on the list of
active pages.
Note #2, inheriting role.invalid when creating child shadow pages is also
far from ideal; that flaw will be addressed separately. |
| In the Linux kernel, the following vulnerability has been resolved:
s390/pkey: Check length in PKEY_VERIFYPROTK ioctl
Explicitly check the buffer length request structure provided by
user-space and fail, if it exceeds the buffer size. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb()
l2cap_sock_new_connection_cb() returned l2cap_pi(sk)->chan after
release_sock(parent). Once the parent lock is dropped the newly
enqueued child socket sk is reachable via the accept queue, so another
task can accept and free it before the callback dereferences sk,
resulting in a use-after-free.
Rework the ->new_connection() op so the core, rather than the callback,
owns the child channel's lifetime. The op now receives a pre-allocated
new_chan and returns an errno instead of allocating and returning a
channel. l2cap_new_connection() allocates the child channel and links
it into the conn list via __l2cap_chan_add() before invoking the
callback, so the conn-list reference keeps the channel alive once
release_sock(parent) exposes the socket to other tasks.
Channel configuration that was duplicated in l2cap_sock_init() and the
various new_connection callbacks is consolidated into
l2cap_chan_set_defaults(), which now inherits from the parent channel
when one is supplied. |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: fix use-after-free of the discoverer in tipc_disc_rcv()
bearer_disable() frees b->disc with tipc_disc_delete()'s plain kfree(),
but tipc_disc_rcv() still dereferences b->disc in RX softirq under
rcu_read_lock() (tipc_udp_recv -> tipc_rcv -> tipc_disc_rcv).
L2 bearers are safe thanks to the synchronize_net() in
tipc_disable_l2_media(), but the UDP bearer defers that call to the
cleanup_bearer() workqueue, so the discoverer is freed with no grace
period:
BUG: KASAN: slab-use-after-free in tipc_disc_rcv (net/tipc/discover.c:149)
Read of size 8 at addr ffff88802348b728 by task poc_tipc/184
<IRQ>
tipc_disc_rcv (net/tipc/discover.c:149)
tipc_rcv (net/tipc/node.c:2126)
tipc_udp_recv (net/tipc/udp_media.c:391)
udp_rcv (net/ipv4/udp.c:2643)
ip_local_deliver_finish (net/ipv4/ip_input.c:241)
</IRQ>
Freed by task 181:
kfree (mm/slub.c:6565)
bearer_disable (net/tipc/bearer.c:418)
tipc_nl_bearer_disable (net/tipc/bearer.c:1001)
The bearer is freed with kfree_rcu(); free the discoverer the same way.
Add an rcu_head to struct tipc_discoverer and free it and its skb from an
RCU callback.
Because the RCU callback (tipc_disc_free_rcu) lives in module text, a
call_rcu() that is still pending when the tipc module is unloaded would
invoke a freed function. Add an rcu_barrier() to tipc_exit() after the
bearer subsystem has been torn down, so all pending discoverer callbacks
have run before the module text goes away.
Reachable from an unprivileged user namespace: the TIPCv2 genl family is
netnsok and its bearer commands have no GENL_ADMIN_PERM. Needs CONFIG_TIPC
and CONFIG_TIPC_MEDIA_UDP. |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: cls_api: Handle TC_ACT_CONSUMED in tcf_qevent_handle
tcf_classify() can return TC_ACT_CONSUMED while the skb is held by the
defragmentation engine (e.g. act_ct on out-of-order fragments). When
that happens the skb is no longer owned by the caller and must not be
touched again.
tcf_qevent_handle() did not handle TC_ACT_CONSUMED: it fell through the
switch and returned the skb to the caller as if classification had
passed. The only qdisc that wires up qevents today is RED, via three call sites
(qe_mark on RED_PROB_MARK/HARD_MARK, qe_early_drop on congestion_drop)
red_enqueue() was continuing to operate on an skb it no longer owns in this
case -- enqueueing it, dropping it, or updating statistics. Resulting in a UAF.
tc qdisc add dev eth0 root handle 1: red ... qevent early_drop block 10
tc filter add block 10 ... action ct
(with ct defrag enabled and traffic that produces out-of-order
fragments, e.g. a fragmented UDP stream)
Handle TC_ACT_CONSUMED in tcf_qevent_handle() the same way the ingress
and egress fast paths do: treat it as stolen and return NULL without
touching the skb. Unlike the TC_ACT_STOLEN case, the skb must not be
dropped/freed here, as it is no longer owned by us. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: fix MLE defragmentation
If either reconf or EPCS multi-link element (MLE) is contained in
a non-transmitted profile, the defragmentation routine is called
with a pointer to the defragmented copy, but the original elements.
This is incorrect for two reasons:
- if the original defragmentation was needed, it will not find the
correct data
- if the original frame is at a higher address, the parsing will
potentially overrun the heap data (though given the layout of
the buffers, only into the new defragmentation buffer, and then
it has to stop and fail once that's filled with copied data.
Fix it by tracking the container along with the pointer and in
doing so also unify the two almost identical defragmentation
routines. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: ebtables: zero chainstack array
sashiko reports:
looking at ebtables table
translation, could a sparse cpu_possible_mask lead to an uninitialized pointer
free?
If cpu_possible_mask is sparse (for example, CPU 0 and CPU 2 are possible,
but CPU 1 is not), the allocation loop skips CPU 1. If vmalloc_node() fails at
CPU 2, the cleanup loop will blindly decrement and call vfree() on
newinfo->chainstack[1].
Not a real-world bug, such allocation isn't expected to fail
in the first place. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: bnep: pin L2CAP connection during netdev registration
bnep_add_connection() reads the L2CAP connection without holding the
channel lock, then passes its HCI device to register_netdev(). Controller
teardown can clear and release that connection concurrently, leaving the
network device registration path to dereference a freed parent device.
Take a reference to the L2CAP connection while holding the channel lock.
Retain it until register_netdev() has taken the parent device reference. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: validate option length before reading conf opt value
l2cap_get_conf_opt() derives the option length from the
attacker-controlled opt->len field and immediately dereferences
opt->val (as u8, get_unaligned_le16() or get_unaligned_le32(), or a
raw pointer for the default case) before any caller has confirmed
that opt->len bytes are present in the buffer. The callers
(l2cap_parse_conf_req(), l2cap_parse_conf_rsp() and
l2cap_conf_rfc_get()) only detect a malformed option afterwards, once
the running length has gone negative, by which point the
out-of-bounds read has already executed.
An existing post-hoc length check keeps the garbage value from being
consumed, so this is not a data leak in the current control flow. It
is still a validate-after-use ordering bug: up to 4 bytes are read
past the end of the buffer before it is known to contain them, and it
is fragile to future changes in the callers.
Fix it at the source. Pass the end of the buffer into
l2cap_get_conf_opt() and refuse to touch opt->val unless the full
option (header + value) fits. Each caller computes an end pointer
once before the loop and checks the return value directly instead of
inferring the error from a negative length. |
| In the Linux kernel, the following vulnerability has been resolved:
sched/rt: Have RT_PUSH_IPI be default off for non PREEMPT_RT
RT migration is done aggressively. When a CPU schedules out a high
priority RT task for a lower priority task, it will look to see if there's
any RT tasks that are waiting to run on another CPU that is of higher
priority than the task this CPU is about to run. If it finds one, it will
pull that task over to the CPU and allow it to run there instead.
Normally, this pulling is done by looking at the RT overloaded mask (rto)
which contains all the CPUs in the scheduler domain with RT tasks that are
waiting to run due to a higher priority RT task currently running on their
CPU. The CPU that is about to schedule a lower priority task will grab the
rq lock of the overloaded CPU and move the RT task from that CPU's runqueue
to the local one and schedule the higher priority RT task.
This caused issues when a lot of CPUs would schedule a lower priority task
at the same time. They would all try to grab the same runqueue lock of
the CPU with the overloaded RT tasks. Only the first CPU that got in will
get that task. All the others would wait until they got the runqueue lock
and see there's nothing to pull and do nothing. On systems with lots of
CPUs, this caused a large latency (up to 500us) which is beyond what
PREEMPT_RT is to allow.
The solution to that was to create an RT_PUSH_IPI logic. When any CPU
wanted to pull a task, instead of grabbing the runqueue lock of the
overloaded CPU, it would start by sending an IPI to the overloaded CPU,
and that IPI handler would have the CPU with the waiting RT task do a push
instead. Then that handler would send an IPI to the next CPU with
overloaded RT tasks, and so on. Note, after the first CPU starts this
process, if another CPU wanted to do a pull, it would see that the process
has already begun and would only increment a counter to have the IPIs
continue again.
The RT_PUSH_IPI solved the latency problem with PREEMPT_RT but could cause
a new issue with non PREEMPT_RT. Namely, softirqs run in a threaded
context on PREEMPT_RT but they can run in an interrupt context in non-RT.
If an IPI lands on a CPU that has just woken up multiple RT tasks and the
current CPU is running a non RT or a low priority RT task, instead of
doing a push, it would simply do a schedule on that CPU. But if a softirq
was also executing on this CPU, the schedule would need to wait until the
softirq finished. Until then, the CPU would still be considered overloaded
as there are RT tasks still waiting to run on it.
A live lock occurred on a workload that was doing heavy networking traffic
on a large machine where the softirqs would run 500us out of 750us. And it
would also be waking up RT tasks, causing the RT pull logic to be
constantly executed.
When a softirq triggered on a CPU with RT tasks queued but not running
yet, and the other CPUs would see this CPU as being overloaded, they would
send an IPI over to it. The CPU would notice that the waiting RT tasks are
of higher priority than the currently running task and simply schedule
that CPU instead. But because the softirq was executing, before it could
schedule, it would receive another IPI to do the same. The amount of IPIs
would slow down the currently running softirq so much that before it could
return back to task context, it would execute another softirq never
allowing the CPU to schedule. This live locked that CPU.
As RT_PUSH_IPI was created to help PREEMPT_RT, make it default off if
PREEMPT_RT is not enabled. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/slab: do not limit zeroing to orig_size when only red zoning is enabled
When init (zeroing) on allocation is requested, for kmalloc() we
generally have to zero the full object size even if a smaller size is
requested, in order to provide krealloc()'s __GFP_ZERO guarantees.
But if we track the requested size, krealloc() uses that information to
do the right thing, so we can zero only the requested size. With red
zoning also enabled, any extra size became part of the red zone, so it
must not be zeroed and thus we must zero only the requested size.
However the current check is imprecise, and will trigger also when only
SLAB_RED_ZONE is enabled without SLAB_STORE_USER (which enables tracking
the requested size). This means enabling red zoning alone can compromise
krealloc()'s __GFP_ZERO contract.
Fix this by using slub_debug_orig_size() instead, which is the exact
check for whether the requested size is tracked. We don't need to care
if red zoning is also enabled or not. Also update and expand the
comment accordingly. |
