๐จ CVE-2026-64406
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: fix UAF in bt_accept_dequeue()
bt_accept_get() takes a temporary reference before dropping the accept
queue lock. bt_accept_dequeue() currently drops that reference before
bt_accept_unlink(), leaving only the queue reference.
bt_accept_unlink() drops the queue reference. The subsequent
sock_hold() therefore accesses freed memory if it was the final
reference, as observed by KASAN during listening L2CAP socket cleanup.
Retain the temporary queue-walk reference through unlink and hand it to
the caller on success. Drop it explicitly on the closed and
not-yet-connected paths.
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: fix UAF in bt_accept_dequeue()
bt_accept_get() takes a temporary reference before dropping the accept
queue lock. bt_accept_dequeue() currently drops that reference before
bt_accept_unlink(), leaving only the queue reference.
bt_accept_unlink() drops the queue reference. The subsequent
sock_hold() therefore accesses freed memory if it was the final
reference, as observed by KASAN during listening L2CAP socket cleanup.
Retain the temporary queue-walk reference through unlink and hand it to
the caller on success. Drop it explicitly on the closed and
not-yet-connected paths.
๐@cveNotify
๐จ CVE-2026-64407
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btnxpuart: Fix out-of-bounds firmware read in nxp_recv_fw_req_v3()
During the v3 firmware download the controller sends a v3_data_req with a
32 bit offset and a 16 bit len. nxp_recv_fw_req_v3() checks only the lower
bound of the offset and then sends firmware from that offset.
nxpdev->fw_dnld_v3_offset = offset - nxpdev->fw_v3_offset_correction;
serdev_device_write_buf(nxpdev->serdev, nxpdev->fw->data +
nxpdev->fw_dnld_v3_offset, len);
Nothing checks that fw_dnld_v3_offset + len stays within nxpdev->fw->size,
so a controller that asks for an offset or length past the firmware image
makes the driver read past the end of nxpdev->fw->data and send that
memory back over UART.
nxp_recv_fw_req_v1() already bounds the same write. Add the equivalent
check to the v3 path, reject the request when it falls outside the firmware
image, and zero len on the error path so the fw_v3_prev_sent bookkeeping at
free_skb stays consistent.
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btnxpuart: Fix out-of-bounds firmware read in nxp_recv_fw_req_v3()
During the v3 firmware download the controller sends a v3_data_req with a
32 bit offset and a 16 bit len. nxp_recv_fw_req_v3() checks only the lower
bound of the offset and then sends firmware from that offset.
nxpdev->fw_dnld_v3_offset = offset - nxpdev->fw_v3_offset_correction;
serdev_device_write_buf(nxpdev->serdev, nxpdev->fw->data +
nxpdev->fw_dnld_v3_offset, len);
Nothing checks that fw_dnld_v3_offset + len stays within nxpdev->fw->size,
so a controller that asks for an offset or length past the firmware image
makes the driver read past the end of nxpdev->fw->data and send that
memory back over UART.
nxp_recv_fw_req_v1() already bounds the same write. Add the equivalent
check to the v3 path, reject the request when it falls outside the firmware
image, and zero len on the error path so the fw_v3_prev_sent bookkeeping at
free_skb stays consistent.
๐@cveNotify
๐จ CVE-2026-64408
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.
๐@cveNotify
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.
๐@cveNotify
๐จ CVE-2026-64409
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btmtksdio: fix infinite loop in btmtksdio_txrx_work()
Every once in a while we see a hung btmtksdio_flush() task:
INFO: task kworker/u17:0:189 blocked for more than 122 seconds.
__cancel_work_timer+0x3f4/0x460
cancel_work_sync+0x1c/0x2c
btmtksdio_flush+0x2c/0x40
hci_dev_open_sync+0x10c4/0x2190
[..]
It all boils down to incorrect time_is_before_jiffies() usage in
btmtksdio_txrx_work(). The btmtksdio_txrx_work() loop is expected
to be terminated if running for longer than 5*HZ. However the
timeout check is twisted: time_is_before_jiffies(old_jiffies + 5*HZ)
evaluates to true when old_jiffies + 5*HZ is in the past i.e. when a
timeout has occurred. Using OR with time_is_before_jiffies(txrx_timeout)
means that:
- before the 5-second timeout: the condition is `int_status || false`,
so it loops as long as there are pending interrupts.
- after the 5-second timeout: the condition becomes `int_status || true`,
which is always true.
When the loop becomes infinite btmtksdio_txrx_work() loop never
terminates and never releases the SDIO host.
Fix loop termination condition to actually enforce a 5*HZ timeout.
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btmtksdio: fix infinite loop in btmtksdio_txrx_work()
Every once in a while we see a hung btmtksdio_flush() task:
INFO: task kworker/u17:0:189 blocked for more than 122 seconds.
__cancel_work_timer+0x3f4/0x460
cancel_work_sync+0x1c/0x2c
btmtksdio_flush+0x2c/0x40
hci_dev_open_sync+0x10c4/0x2190
[..]
It all boils down to incorrect time_is_before_jiffies() usage in
btmtksdio_txrx_work(). The btmtksdio_txrx_work() loop is expected
to be terminated if running for longer than 5*HZ. However the
timeout check is twisted: time_is_before_jiffies(old_jiffies + 5*HZ)
evaluates to true when old_jiffies + 5*HZ is in the past i.e. when a
timeout has occurred. Using OR with time_is_before_jiffies(txrx_timeout)
means that:
- before the 5-second timeout: the condition is `int_status || false`,
so it loops as long as there are pending interrupts.
- after the 5-second timeout: the condition becomes `int_status || true`,
which is always true.
When the loop becomes infinite btmtksdio_txrx_work() loop never
terminates and never releases the SDIO host.
Fix loop termination condition to actually enforce a 5*HZ timeout.
๐@cveNotify
๐จ CVE-2026-64410
In the Linux kernel, the following vulnerability has been resolved:
netfilter: flowtable: IPIP tunnel hardware offload is not yet support
No driver supports for IPIP tunnels yet, give up early on setting up the
hardware offload for this scenario.
This patch adds a stub that can be enhanced to add more configuration
that are currently not supported. As of now, the offload work is
enqueued to the worker, then ignored if the hardware offload
configuration is not supported.
Check the NF_FLOW_HW flag to know if this entry was already tried once
to be offloaded so this is not retried on refresh when unsupported. Move
NF_FLOW_HW flag check to nf_flow_offload_add(). If this NF_FLOW_HW flag
is unset the _del and _stats variants are never called.
This can be updated later on to skip hardware offload work to be queued
in case hardware offload does not support it.
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
netfilter: flowtable: IPIP tunnel hardware offload is not yet support
No driver supports for IPIP tunnels yet, give up early on setting up the
hardware offload for this scenario.
This patch adds a stub that can be enhanced to add more configuration
that are currently not supported. As of now, the offload work is
enqueued to the worker, then ignored if the hardware offload
configuration is not supported.
Check the NF_FLOW_HW flag to know if this entry was already tried once
to be offloaded so this is not retried on refresh when unsupported. Move
NF_FLOW_HW flag check to nf_flow_offload_add(). If this NF_FLOW_HW flag
is unset the _del and _stats variants are never called.
This can be updated later on to skip hardware offload work to be queued
in case hardware offload does not support it.
๐@cveNotify
๐จ CVE-2026-64411
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ebtables: terminate table name before find_table_lock()
update_counters() and compat_update_counters() forward a user-supplied
32-byte table name to find_table_lock() without NUL-terminating it. On a
lookup miss, find_inlist_lock() calls try_then_request_module(..., "%s%s",
"ebtable_", name), and vsnprintf() reads past the name field and the
stack object until it hits a zero byte.
BUG: KASAN: stack-out-of-bounds in string (lib/vsprintf.c:648 lib/vsprintf.c:730)
Read of size 1 at addr ffff8880119dfb20 by task exploit/147
Call Trace:
...
string (lib/vsprintf.c:648 lib/vsprintf.c:730)
vsnprintf (lib/vsprintf.c:2945)
__request_module (kernel/module/kmod.c:150)
do_update_counters.isra.0 (net/bridge/netfilter/ebtables.c:371 net/bridge/netfilter/ebtables.c:380)
update_counters (net/bridge/netfilter/ebtables.c:1440)
do_ebt_set_ctl (net/bridge/netfilter/ebtables.c:2573)
nf_setsockopt (net/netfilter/nf_sockopt.c:101)
ip_setsockopt (net/ipv4/ip_sockglue.c:1424)
raw_setsockopt (net/ipv4/raw.c:847)
__sys_setsockopt (net/socket.c:2393)
...
compat_do_replace() shares the same unterminated name via
compat_copy_ebt_replace_from_user(); terminate it there too so all
find_table_lock() callers behave alike. The other callers already
terminate the name after the copy.
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ebtables: terminate table name before find_table_lock()
update_counters() and compat_update_counters() forward a user-supplied
32-byte table name to find_table_lock() without NUL-terminating it. On a
lookup miss, find_inlist_lock() calls try_then_request_module(..., "%s%s",
"ebtable_", name), and vsnprintf() reads past the name field and the
stack object until it hits a zero byte.
BUG: KASAN: stack-out-of-bounds in string (lib/vsprintf.c:648 lib/vsprintf.c:730)
Read of size 1 at addr ffff8880119dfb20 by task exploit/147
Call Trace:
...
string (lib/vsprintf.c:648 lib/vsprintf.c:730)
vsnprintf (lib/vsprintf.c:2945)
__request_module (kernel/module/kmod.c:150)
do_update_counters.isra.0 (net/bridge/netfilter/ebtables.c:371 net/bridge/netfilter/ebtables.c:380)
update_counters (net/bridge/netfilter/ebtables.c:1440)
do_ebt_set_ctl (net/bridge/netfilter/ebtables.c:2573)
nf_setsockopt (net/netfilter/nf_sockopt.c:101)
ip_setsockopt (net/ipv4/ip_sockglue.c:1424)
raw_setsockopt (net/ipv4/raw.c:847)
__sys_setsockopt (net/socket.c:2393)
...
compat_do_replace() shares the same unterminated name via
compat_copy_ebt_replace_from_user(); terminate it there too so all
find_table_lock() callers behave alike. The other callers already
terminate the name after the copy.
๐@cveNotify
๐จ CVE-2026-64412
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ebtables: module names must be null-terminated
We need to explicitly check the length, else we may pass non-null
terminated string to request_module().
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ebtables: module names must be null-terminated
We need to explicitly check the length, else we may pass non-null
terminated string to request_module().
๐@cveNotify
๐จ CVE-2026-64413
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.
๐@cveNotify
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.
๐@cveNotify
๐จ CVE-2026-64414
In the Linux kernel, the following vulnerability has been resolved:
netfilter: handle unreadable frags
sashiko reports:
When an skb with unreadable fragments (such as from devmem TCP, where
skb_frags_readable(skb) returns false) is processed by the u32 module,
skb_copy_bits() will safely return a negative error code [..]
xt_u32: bail out with hotdrop in this case.
gather_frags: return -1, just as if we had no fragment header.
nfnetlink_queue: restrict to the linear part.
nfnetlink_log: restrict to the linear part.
v2:
- skb_zerocopy helpers don't copy readable flag, i.e. nfnetlink_queue
is broken too
xt_u32 shouldn't return true if hotdrop was set.
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
netfilter: handle unreadable frags
sashiko reports:
When an skb with unreadable fragments (such as from devmem TCP, where
skb_frags_readable(skb) returns false) is processed by the u32 module,
skb_copy_bits() will safely return a negative error code [..]
xt_u32: bail out with hotdrop in this case.
gather_frags: return -1, just as if we had no fragment header.
nfnetlink_queue: restrict to the linear part.
nfnetlink_log: restrict to the linear part.
v2:
- skb_zerocopy helpers don't copy readable flag, i.e. nfnetlink_queue
is broken too
xt_u32 shouldn't return true if hotdrop was set.
๐@cveNotify
๐จ CVE-2026-64415
In the Linux kernel, the following vulnerability has been resolved:
mm/swap: add cond_resched() in swap_reclaim_full_clusters to prevent softlockup
We hit a real softlockup in an internal stress test environment. The
workload was LTP memory/swap stress on a large arm64 machine, with 320
CPUs, about 1TB memory and an 8.6GB swap device. The system was under
heavy load and the swap device had a large number of full clusters. The
softlockup was triggered during a stress test after about 3 days.
So, add periodic cond_resched() calls during large full_clusters
reclaim operations to prevent softlockup issues.
Detailed call trace as follow:
PID: 3817773 TASK: ffff0883bb28b780 CPU: 48 COMMAND: "kworker/48:7"
#0 [ffff800080183d10] __crash_kexec at ffffa4c1361e5de4
#1 [ffff800080183d90] panic at ffffa4c1360d5e9c
#2 [ffff800080183e20] watchdog_timer_fn at ffffa4c136231fa8
...
#16 [ffff8000c4ad3cb0] swap_cache_del_folio at ffffa4c1363e1614
#17 [ffff8000c4ad3ce0] __try_to_reclaim_swap at ffffa4c1363e4bfc
#18 [ffff8000c4ad3d40] swap_reclaim_full_clusters at ffffa4c1363e5474
#19 [ffff8000c4ad3da0] swap_reclaim_work at ffffa4c1363e550c
#20 [ffff8000c4ad3dc0] process_one_work at ffffa4c136102edc
#21 [ffff8000c4ad3e10] worker_thread at ffffa4c136103398
#22 [ffff8000c4ad3e70] kthread at ffffa4c13610d95c
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
mm/swap: add cond_resched() in swap_reclaim_full_clusters to prevent softlockup
We hit a real softlockup in an internal stress test environment. The
workload was LTP memory/swap stress on a large arm64 machine, with 320
CPUs, about 1TB memory and an 8.6GB swap device. The system was under
heavy load and the swap device had a large number of full clusters. The
softlockup was triggered during a stress test after about 3 days.
So, add periodic cond_resched() calls during large full_clusters
reclaim operations to prevent softlockup issues.
Detailed call trace as follow:
PID: 3817773 TASK: ffff0883bb28b780 CPU: 48 COMMAND: "kworker/48:7"
#0 [ffff800080183d10] __crash_kexec at ffffa4c1361e5de4
#1 [ffff800080183d90] panic at ffffa4c1360d5e9c
#2 [ffff800080183e20] watchdog_timer_fn at ffffa4c136231fa8
...
#16 [ffff8000c4ad3cb0] swap_cache_del_folio at ffffa4c1363e1614
#17 [ffff8000c4ad3ce0] __try_to_reclaim_swap at ffffa4c1363e4bfc
#18 [ffff8000c4ad3d40] swap_reclaim_full_clusters at ffffa4c1363e5474
#19 [ffff8000c4ad3da0] swap_reclaim_work at ffffa4c1363e550c
#20 [ffff8000c4ad3dc0] process_one_work at ffffa4c136102edc
#21 [ffff8000c4ad3e10] worker_thread at ffffa4c136103398
#22 [ffff8000c4ad3e70] kthread at ffffa4c13610d95c
๐@cveNotify
๐จ CVE-2026-64416
In the Linux kernel, the following vulnerability has been resolved:
mm: swap_cgroup: fix NULL deref in lookup_swap_cgroup_id on swapless host
lookup_swap_cgroup_id() passes swap_cgroup_ctrl[type].map to
__swap_cgroup_id_lookup() without checking that the type was ever
registered via swap_cgroup_swapon(). On a swapless host every ctrl->map
is NULL, so __swap_cgroup_id_lookup() dereferences NULL + a scaled
swp_offset().
Since commit bea67dcc5eea ("mm: attempt to batch free swap entries for
zap_pte_range()"), zap_pte_range() -> swap_pte_batch() calls
lookup_swap_cgroup_id() on any non-present, non-none PTE that decodes as a
real swap entry, without first validating it against swap_info[]. A
single PTE corrupted into a type-0 swap entry takes the host down at
process exit.
We hit this in production on a swapless 6.12.58 host: ~1s of
"get_swap_device: Bad swap file entry 3f800204222bb" (do_swap_page() being
correctly defensive about the same entry) followed by
BUG: unable to handle page fault for address: 000003f800204220
RIP: 0010:lookup_swap_cgroup_id+0x2b/0x60
Call Trace:
swap_pte_batch+0xbf/0x230
zap_pte_range+0x4c8/0x780
unmap_page_range+0x190/0x3e0
exit_mmap+0xd9/0x3c0
do_exit+0x20c/0x4b0
syzbot has reported the identical stack.
The source of the PTE corruption is a separate bug; this change makes the
teardown path as robust as the fault path already is. Every other caller
of lookup_swap_cgroup_id() is downstream of a get_swap_device() that has
already validated the entry, so the new branch is cold.
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
mm: swap_cgroup: fix NULL deref in lookup_swap_cgroup_id on swapless host
lookup_swap_cgroup_id() passes swap_cgroup_ctrl[type].map to
__swap_cgroup_id_lookup() without checking that the type was ever
registered via swap_cgroup_swapon(). On a swapless host every ctrl->map
is NULL, so __swap_cgroup_id_lookup() dereferences NULL + a scaled
swp_offset().
Since commit bea67dcc5eea ("mm: attempt to batch free swap entries for
zap_pte_range()"), zap_pte_range() -> swap_pte_batch() calls
lookup_swap_cgroup_id() on any non-present, non-none PTE that decodes as a
real swap entry, without first validating it against swap_info[]. A
single PTE corrupted into a type-0 swap entry takes the host down at
process exit.
We hit this in production on a swapless 6.12.58 host: ~1s of
"get_swap_device: Bad swap file entry 3f800204222bb" (do_swap_page() being
correctly defensive about the same entry) followed by
BUG: unable to handle page fault for address: 000003f800204220
RIP: 0010:lookup_swap_cgroup_id+0x2b/0x60
Call Trace:
swap_pte_batch+0xbf/0x230
zap_pte_range+0x4c8/0x780
unmap_page_range+0x190/0x3e0
exit_mmap+0xd9/0x3c0
do_exit+0x20c/0x4b0
syzbot has reported the identical stack.
The source of the PTE corruption is a separate bug; this change makes the
teardown path as robust as the fault path already is. Every other caller
of lookup_swap_cgroup_id() is downstream of a get_swap_device() that has
already validated the entry, so the new branch is cold.
๐@cveNotify
๐จ CVE-2026-64417
In the Linux kernel, the following vulnerability has been resolved:
mm: shrinker: fix NULL pointer dereference in debugfs
shrinker_debugfs_add() creates both "count" and "scan" debugfs files
unconditionally.
That assumes every shrinker implements both count_objects() and
scan_objects(), which is not guaranteed. For example, the xen-backend
shrinker sets count_objects() but leaves scan_objects() NULL, so writing
to its scan file calls through a NULL function pointer and panics the
kernel:
BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
Call Trace:
<TASK>
shrinker_debugfs_scan_write+0x12e/0x270
full_proxy_write+0x5f/0x90
vfs_write+0xde/0x420
? filp_flush+0x75/0x90
? filp_close+0x1d/0x30
? do_dup2+0xb8/0x120
ksys_write+0x68/0xf0
? filp_flush+0x75/0x90
do_syscall_64+0xb3/0x5b0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The count path has the same issue in principle if a shrinker omits
count_objects().
To fix it, only create "count" and "scan" debugfs files when the
corresponding callbacks are present.
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
mm: shrinker: fix NULL pointer dereference in debugfs
shrinker_debugfs_add() creates both "count" and "scan" debugfs files
unconditionally.
That assumes every shrinker implements both count_objects() and
scan_objects(), which is not guaranteed. For example, the xen-backend
shrinker sets count_objects() but leaves scan_objects() NULL, so writing
to its scan file calls through a NULL function pointer and panics the
kernel:
BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
Call Trace:
<TASK>
shrinker_debugfs_scan_write+0x12e/0x270
full_proxy_write+0x5f/0x90
vfs_write+0xde/0x420
? filp_flush+0x75/0x90
? filp_close+0x1d/0x30
? do_dup2+0xb8/0x120
ksys_write+0x68/0xf0
? filp_flush+0x75/0x90
do_syscall_64+0xb3/0x5b0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The count path has the same issue in principle if a shrinker omits
count_objects().
To fix it, only create "count" and "scan" debugfs files when the
corresponding callbacks are present.
๐@cveNotify
๐จ CVE-2026-64418
In the Linux kernel, the following vulnerability has been resolved:
mm: shrinker: fix shrinker_info teardown race with expansion
expand_shrinker_info() iterates all visible memcgs under shrinker_mutex,
including memcgs that have not finished ->css_online() yet.
Once pn->shrinker_info has been published, teardown must stay serialized
with expand_shrinker_info() until that memcg is either fully online or no
longer visible to iteration. Today alloc_shrinker_info() breaks that rule
by dropping shrinker_mutex before freeing a partially initialized
shrinker_info array, which may cause the following race:
CPU0 CPU1
==== ====
css_create
--> list_add_tail_rcu(&css->sibling, &parent_css->children);
online_css
--> mem_cgroup_css_online
--> alloc_shrinker_info
--> alloc node0 info
rcu_assign_pointer(C->node0->shrinker_info, old0)
alloc node1 info -> FAIL -> goto err
mutex_unlock(shrinker_mutex)
shrinker_alloc()
--> shrinker_memcg_alloc
--> mutex_lock(shrinker_mutex)
expand_shrinker_info
--> mem_cgroup_iter see the memcg
expand_one_shrinker_info
--> old0 = C->node0->shrinker_info
memcpy(new->unit, old0->unit, ...);
free_shrinker_info
--> kvfree(old0);
/* double free !! */
kvfree_rcu(old0, rcu);
The same problem exists later in mem_cgroup_css_online(). If
alloc_shrinker_info() succeeds but a subsequent objcg allocation fails,
the free_objcg -> free_shrinker_info() unwind path tears down the already
published pn->shrinker_info arrays without shrinker_mutex. The
expand_one_shrinker_info() can race with that teardown in the same way,
leading to use-after-free or double-free of the old shrinker_info.
Fix this by serializing shrinker_info teardown with shrinker_mutex, and by
keeping alloc_shrinker_info() error cleanup inside the locked section.
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
mm: shrinker: fix shrinker_info teardown race with expansion
expand_shrinker_info() iterates all visible memcgs under shrinker_mutex,
including memcgs that have not finished ->css_online() yet.
Once pn->shrinker_info has been published, teardown must stay serialized
with expand_shrinker_info() until that memcg is either fully online or no
longer visible to iteration. Today alloc_shrinker_info() breaks that rule
by dropping shrinker_mutex before freeing a partially initialized
shrinker_info array, which may cause the following race:
CPU0 CPU1
==== ====
css_create
--> list_add_tail_rcu(&css->sibling, &parent_css->children);
online_css
--> mem_cgroup_css_online
--> alloc_shrinker_info
--> alloc node0 info
rcu_assign_pointer(C->node0->shrinker_info, old0)
alloc node1 info -> FAIL -> goto err
mutex_unlock(shrinker_mutex)
shrinker_alloc()
--> shrinker_memcg_alloc
--> mutex_lock(shrinker_mutex)
expand_shrinker_info
--> mem_cgroup_iter see the memcg
expand_one_shrinker_info
--> old0 = C->node0->shrinker_info
memcpy(new->unit, old0->unit, ...);
free_shrinker_info
--> kvfree(old0);
/* double free !! */
kvfree_rcu(old0, rcu);
The same problem exists later in mem_cgroup_css_online(). If
alloc_shrinker_info() succeeds but a subsequent objcg allocation fails,
the free_objcg -> free_shrinker_info() unwind path tears down the already
published pn->shrinker_info arrays without shrinker_mutex. The
expand_one_shrinker_info() can race with that teardown in the same way,
leading to use-after-free or double-free of the old shrinker_info.
Fix this by serializing shrinker_info teardown with shrinker_mutex, and by
keeping alloc_shrinker_info() error cleanup inside the locked section.
๐@cveNotify
๐จ CVE-2026-64419
In the Linux kernel, the following vulnerability has been resolved:
mm/shrinker: do not hold RCU lock in shrinker_debugfs_count_show()
Reading the debugfs "count" file of a memcg-aware shrinker can sleep
inside an RCU read-side critical section:
BUG: sleeping function called from invalid context at kernel/cgroup/rstat.c:421
RCU nest depth: 1, expected: 0
css_rstat_flush
mem_cgroup_flush_stats
zswap_shrinker_count
shrinker_debugfs_count_show
shrinker_debugfs_count_show() invokes the ->count_objects() callback under
rcu_read_lock(). The zswap callback flushes memcg stats via
css_rstat_flush(), which may sleep, so it must not run under RCU.
The RCU lock is not needed here. mem_cgroup_iter() takes RCU internally
and returns a memcg holding a css reference (dropped on the next iteration
or by mem_cgroup_iter_break()), so the memcg stays alive without it. The
shrinker is kept alive by the open debugfs file: shrinker_free() removes
the debugfs entries via debugfs_remove_recursive(), which waits for
in-flight readers to drain, before call_rcu(..., shrinker_free_rcu_cb).
The sibling "scan" handler already invokes the sleeping ->scan_objects()
callback with no RCU section.
Drop the rcu_read_lock()/rcu_read_unlock().
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
mm/shrinker: do not hold RCU lock in shrinker_debugfs_count_show()
Reading the debugfs "count" file of a memcg-aware shrinker can sleep
inside an RCU read-side critical section:
BUG: sleeping function called from invalid context at kernel/cgroup/rstat.c:421
RCU nest depth: 1, expected: 0
css_rstat_flush
mem_cgroup_flush_stats
zswap_shrinker_count
shrinker_debugfs_count_show
shrinker_debugfs_count_show() invokes the ->count_objects() callback under
rcu_read_lock(). The zswap callback flushes memcg stats via
css_rstat_flush(), which may sleep, so it must not run under RCU.
The RCU lock is not needed here. mem_cgroup_iter() takes RCU internally
and returns a memcg holding a css reference (dropped on the next iteration
or by mem_cgroup_iter_break()), so the memcg stays alive without it. The
shrinker is kept alive by the open debugfs file: shrinker_free() removes
the debugfs entries via debugfs_remove_recursive(), which waits for
in-flight readers to drain, before call_rcu(..., shrinker_free_rcu_cb).
The sibling "scan" handler already invokes the sleeping ->scan_objects()
callback with no RCU section.
Drop the rcu_read_lock()/rcu_read_unlock().
๐@cveNotify
๐จ CVE-2026-64425
In the Linux kernel, the following vulnerability has been resolved:
io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item
commit 10dc95939817 ("io_uring/io-wq: check IO_WQ_BIT_EXIT inside work
run loop") fixed the obvious case where io_worker_handle_work() took one
exit-bit snapshot before draining pending work, but the fix stops one
level too early.
io_worker_handle_work() now re-checks IO_WQ_BIT_EXIT in its outer work
run loop, yet it still snapshots that bit once before processing a whole
dependent linked-work chain. If io_wq_exit_start() sets IO_WQ_BIT_EXIT
after the first linked item has started, the remaining linked items can
still reuse stale do_kill = false, skip IO_WQ_WORK_CANCEL, and continue
running after exit has begun.
Move the check further inside, so it covers linked items too. Note: this
is a syzbot special as it loves setting up tons of slow linked work on
weird devices like msr that take forever to read, and immediately close
the ring. Exit then takes a long time.
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item
commit 10dc95939817 ("io_uring/io-wq: check IO_WQ_BIT_EXIT inside work
run loop") fixed the obvious case where io_worker_handle_work() took one
exit-bit snapshot before draining pending work, but the fix stops one
level too early.
io_worker_handle_work() now re-checks IO_WQ_BIT_EXIT in its outer work
run loop, yet it still snapshots that bit once before processing a whole
dependent linked-work chain. If io_wq_exit_start() sets IO_WQ_BIT_EXIT
after the first linked item has started, the remaining linked items can
still reuse stale do_kill = false, skip IO_WQ_WORK_CANCEL, and continue
running after exit has begun.
Move the check further inside, so it covers linked items too. Note: this
is a syzbot special as it loves setting up tons of slow linked work on
weird devices like msr that take forever to read, and immediately close
the ring. Exit then takes a long time.
๐@cveNotify
๐จ CVE-2026-48710
Starlette is a lightweight ASGI framework/toolkit. Prior to version 1.0.1, the HTTP `Host` request header was not validated before being used to reconstruct `request.url`. Because the routing algorithm relies on the raw HTTP path while `request.url` is rebuilt from the `Host` header, a malformed header could make `request.url.path` differ from the path that was actually requested. Middleware and endpoints that apply security restrictions based on `request.url` (rather than the raw `scope` path) could therefore be bypassed. Users should upgrade to a version greater than or equal to version 1.0.1, which validates the `Host` header against the grammar of RFC 9112 ยง3.2 / RFC 3986 ยง3.2.2 when constructing `request.url` and falls back to `scope["server"]` for malformed values.
๐@cveNotify
Starlette is a lightweight ASGI framework/toolkit. Prior to version 1.0.1, the HTTP `Host` request header was not validated before being used to reconstruct `request.url`. Because the routing algorithm relies on the raw HTTP path while `request.url` is rebuilt from the `Host` header, a malformed header could make `request.url.path` differ from the path that was actually requested. Middleware and endpoints that apply security restrictions based on `request.url` (rather than the raw `scope` path) could therefore be bypassed. Users should upgrade to a version greater than or equal to version 1.0.1, which validates the `Host` header against the grammar of RFC 9112 ยง3.2 / RFC 3986 ยง3.2.2 when constructing `request.url` and falls back to `scope["server"]` for malformed values.
๐@cveNotify
CVE-2026-48710 - Nemesis - BadHost
BadHost - CVE-2026-48710 Starlette Host-Header Auth Bypass
The critical Starlette auth bypass CVE-2026-48710 (BadHost). Affects FastAPI, MCP servers, LLM proxies, AI agent frameworks, and thousands of Python ASGI apps.
๐จ CVE-2026-64355
In the Linux kernel, the following vulnerability has been resolved:
bpf: Reject fragmented frames in devmap
Devmap broadcast redirects clone the packet for all but the last
destination.
For native XDP, that clone path copies only the linear xdp_frame data,
while fragmented frames keep skb_shared_info in tailroom outside the
linear area. Cloning such a frame leaves XDP_FLAGS_HAS_FRAGS set but
without valid frag metadata, and the later free path can interpret
uninitialized tail data as skb_shared_info, leading to an out-of-bounds
access during frame return.
Reject fragmented native XDP frames in dev_map_enqueue_clone().
Add the same restriction to the generic XDP clone path in
dev_map_redirect_clone(). Generic XDP represents fragmented packets as
nonlinear skbs, and rejecting them here keeps clone-based broadcast
support aligned between native and generic XDP.
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
bpf: Reject fragmented frames in devmap
Devmap broadcast redirects clone the packet for all but the last
destination.
For native XDP, that clone path copies only the linear xdp_frame data,
while fragmented frames keep skb_shared_info in tailroom outside the
linear area. Cloning such a frame leaves XDP_FLAGS_HAS_FRAGS set but
without valid frag metadata, and the later free path can interpret
uninitialized tail data as skb_shared_info, leading to an out-of-bounds
access during frame return.
Reject fragmented native XDP frames in dev_map_enqueue_clone().
Add the same restriction to the generic XDP clone path in
dev_map_redirect_clone(). Generic XDP represents fragmented packets as
nonlinear skbs, and rejecting them here keeps clone-based broadcast
support aligned between native and generic XDP.
๐@cveNotify
๐จ CVE-2026-64356
In the Linux kernel, the following vulnerability has been resolved:
xfs: fix memory leak in xfs_dqinode_metadir_create()
If xfs_metadir_create() fails in xfs_dqinode_metadir_create(), the current
code returns directly, leaking the allocated update and transaction state.
If the subsequent commit fails, the caller-owned inode reference is left
behind.
Fix this memory leak by routing the create failure path through
xfs_metadir_cancel(). For both create and commit failures, finish and
release any inode returned to the caller, mirroring the unwind pattern in
xfs_metadir_mkdir().
The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available. Manual inspection confirms that the bug is still
present in v7.1.1.
An x86_64 allyesconfig build showed no new warnings. Runtime validation
used kprobe fault injection during `mount -o uquota` on a metadir XFS
image. Injecting xfs_metadir_create() reproduced the old active-update path
that left mount stuck later in mount setup; after this change, the same
injection reported cancel_hits=1 and irele_hits=1. Injecting
xfs_metadir_commit() exercised the old inode-reference leak path; after
this change, it reported irele_hits=1.
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
xfs: fix memory leak in xfs_dqinode_metadir_create()
If xfs_metadir_create() fails in xfs_dqinode_metadir_create(), the current
code returns directly, leaking the allocated update and transaction state.
If the subsequent commit fails, the caller-owned inode reference is left
behind.
Fix this memory leak by routing the create failure path through
xfs_metadir_cancel(). For both create and commit failures, finish and
release any inode returned to the caller, mirroring the unwind pattern in
xfs_metadir_mkdir().
The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available. Manual inspection confirms that the bug is still
present in v7.1.1.
An x86_64 allyesconfig build showed no new warnings. Runtime validation
used kprobe fault injection during `mount -o uquota` on a metadir XFS
image. Injecting xfs_metadir_create() reproduced the old active-update path
that left mount stuck later in mount setup; after this change, the same
injection reported cancel_hits=1 and irele_hits=1. Injecting
xfs_metadir_commit() exercised the old inode-reference leak path; after
this change, it reported irele_hits=1.
๐@cveNotify
๐จ CVE-2026-64357
In the Linux kernel, the following vulnerability has been resolved:
xfs: fix exchmaps reservation limit check
xfs_exchmaps_estimate_overhead() adds the bmbt and rmapbt
overhead to a local resblks variable, but the final UINT_MAX
check still tests req->resblks. That is the reservation value
from before the overhead was added.
The computed value is stored back in req->resblks and later passed
to xfs_trans_alloc(), whose block reservation argument is unsigned
int. Check the computed reservation so the existing limit applies
to the value that will be used.
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
xfs: fix exchmaps reservation limit check
xfs_exchmaps_estimate_overhead() adds the bmbt and rmapbt
overhead to a local resblks variable, but the final UINT_MAX
check still tests req->resblks. That is the reservation value
from before the overhead was added.
The computed value is stored back in req->resblks and later passed
to xfs_trans_alloc(), whose block reservation argument is unsigned
int. Check the computed reservation so the existing limit applies
to the value that will be used.
๐@cveNotify
๐จ CVE-2026-64358
In the Linux kernel, the following vulnerability has been resolved:
media: mtk-jpeg: cancel workqueue on release for supported platforms only
Since a recent fix the mtk_jpeg_release function cancels any pending
or running work present in the driver workqueue using
cancel_work_sync function.
Currently, only the multicore based variants use this workqueue and they
have the jpeg_worker platform data field initialized with a workqueue
callback function. For the others, this field value remain NULL by
default.
The cancel_work_sync function is unconditionally called in
mtk_jpeg_release function, even for the variants that do not use the
workqueue. This call generates a WARN_ON print in __flush_work because
the workqueue callback function presence check fails in __flush_work
function (used by cancel_work_sync).
So, to avoid these warnings, call cancel_work_sync only if a workqueue
callback is defined in platform data.
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
media: mtk-jpeg: cancel workqueue on release for supported platforms only
Since a recent fix the mtk_jpeg_release function cancels any pending
or running work present in the driver workqueue using
cancel_work_sync function.
Currently, only the multicore based variants use this workqueue and they
have the jpeg_worker platform data field initialized with a workqueue
callback function. For the others, this field value remain NULL by
default.
The cancel_work_sync function is unconditionally called in
mtk_jpeg_release function, even for the variants that do not use the
workqueue. This call generates a WARN_ON print in __flush_work because
the workqueue callback function presence check fails in __flush_work
function (used by cancel_work_sync).
So, to avoid these warnings, call cancel_work_sync only if a workqueue
callback is defined in platform data.
๐@cveNotify
๐จ CVE-2026-64359
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: reject CLEAN_SEGMENTS ioctl with out-of-range segment numbers
Syzbot reported a hung task in nilfs_transaction_begin() where multiple
tasks performing chmod() on a nilfs2 mount blocked for over 143 seconds
waiting to acquire ns_segctor_sem for read:
INFO: task syz.0.17:5918 blocked for more than 143 seconds.
Call Trace:
schedule+0x164/0x360
rwsem_down_read_slowpath+0x6d9/0x940
down_read+0x99/0x2e0
nilfs_transaction_begin+0x364/0x710 fs/nilfs2/segment.c:221
nilfs_setattr+0x124/0x2c0 fs/nilfs2/inode.c:921
notify_change+0xc1a/0xf40
chmod_common+0x273/0x4a0
do_fchmodat+0x12d/0x230
The writer holding ns_segctor_sem was a concurrent
NILFS_IOCTL_CLEAN_SEGMENTS caller, stuck inside printk while emitting
per-element warnings from nilfs_sufile_updatev():
__nilfs_msg+0x373/0x450 fs/nilfs2/super.c:78
nilfs_sufile_updatev+0x21c/0x6d0 fs/nilfs2/sufile.c:186
nilfs_sufile_freev fs/nilfs2/sufile.h:93 [inline]
nilfs_free_segments fs/nilfs2/segment.c:1140 [inline]
nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1261 [inline]
nilfs_segctor_do_construct+0x1f55/0x76c0
nilfs_clean_segments+0x3bd/0xa50
nilfs_ioctl_clean_segments fs/nilfs2/ioctl.c:922 [inline]
nilfs_ioctl+0x261f/0x2780
The root cause is that user-supplied segment numbers are not validated
before nilfs_clean_segments() begins doing work; the range check on
each segnum is performed deep inside the call chain by
nilfs_sufile_updatev(), which emits a nilfs_warn() per invalid entry
while still holding the segctor lock and the sufile mi_sem. Under load
(repeated invocations across multiple mounts saturating the global
printk path), the cumulative printk latency keeps ns_segctor_sem held
long enough to trip the hung_task watchdog, blocking concurrent
operations such as chmod() that need ns_segctor_sem for read.
Fix by validating the contents of kbufs[4] in nilfs_clean_segments()
immediately after acquiring ns_segctor_sem via nilfs_transaction_lock().
Holding ns_segctor_sem serializes the check against
nilfs_ioctl_resize(), which can modify ns_nsegments, so the validation
uses a consistent value. Out-of-range segment numbers are rejected
with -EINVAL before any segment-cleaning work begins, so the bad
entries never reach the per-element diagnostic path inside
nilfs_sufile_updatev().
๐@cveNotify
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: reject CLEAN_SEGMENTS ioctl with out-of-range segment numbers
Syzbot reported a hung task in nilfs_transaction_begin() where multiple
tasks performing chmod() on a nilfs2 mount blocked for over 143 seconds
waiting to acquire ns_segctor_sem for read:
INFO: task syz.0.17:5918 blocked for more than 143 seconds.
Call Trace:
schedule+0x164/0x360
rwsem_down_read_slowpath+0x6d9/0x940
down_read+0x99/0x2e0
nilfs_transaction_begin+0x364/0x710 fs/nilfs2/segment.c:221
nilfs_setattr+0x124/0x2c0 fs/nilfs2/inode.c:921
notify_change+0xc1a/0xf40
chmod_common+0x273/0x4a0
do_fchmodat+0x12d/0x230
The writer holding ns_segctor_sem was a concurrent
NILFS_IOCTL_CLEAN_SEGMENTS caller, stuck inside printk while emitting
per-element warnings from nilfs_sufile_updatev():
__nilfs_msg+0x373/0x450 fs/nilfs2/super.c:78
nilfs_sufile_updatev+0x21c/0x6d0 fs/nilfs2/sufile.c:186
nilfs_sufile_freev fs/nilfs2/sufile.h:93 [inline]
nilfs_free_segments fs/nilfs2/segment.c:1140 [inline]
nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1261 [inline]
nilfs_segctor_do_construct+0x1f55/0x76c0
nilfs_clean_segments+0x3bd/0xa50
nilfs_ioctl_clean_segments fs/nilfs2/ioctl.c:922 [inline]
nilfs_ioctl+0x261f/0x2780
The root cause is that user-supplied segment numbers are not validated
before nilfs_clean_segments() begins doing work; the range check on
each segnum is performed deep inside the call chain by
nilfs_sufile_updatev(), which emits a nilfs_warn() per invalid entry
while still holding the segctor lock and the sufile mi_sem. Under load
(repeated invocations across multiple mounts saturating the global
printk path), the cumulative printk latency keeps ns_segctor_sem held
long enough to trip the hung_task watchdog, blocking concurrent
operations such as chmod() that need ns_segctor_sem for read.
Fix by validating the contents of kbufs[4] in nilfs_clean_segments()
immediately after acquiring ns_segctor_sem via nilfs_transaction_lock().
Holding ns_segctor_sem serializes the check against
nilfs_ioctl_resize(), which can modify ns_nsegments, so the validation
uses a consistent value. Out-of-range segment numbers are rejected
with -EINVAL before any segment-cleaning work begins, so the bad
entries never reach the per-element diagnostic path inside
nilfs_sufile_updatev().
๐@cveNotify