| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
drm/tegra: Add call to put_pid()
Add a call to put_pid() corresponding to get_task_pid().
host1x_memory_context_alloc() does not take ownership of the PID so we
need to free it here to avoid leaking.
[mperttunen@nvidia.com: reword commit message] |
| In the Linux kernel, the following vulnerability has been resolved:
timers: Fix NULL function pointer race in timer_shutdown_sync()
There is a race condition between timer_shutdown_sync() and timer
expiration that can lead to hitting a WARN_ON in expire_timers().
The issue occurs when timer_shutdown_sync() clears the timer function
to NULL while the timer is still running on another CPU. The race
scenario looks like this:
CPU0 CPU1
<SOFTIRQ>
lock_timer_base()
expire_timers()
base->running_timer = timer;
unlock_timer_base()
[call_timer_fn enter]
mod_timer()
...
timer_shutdown_sync()
lock_timer_base()
// For now, will not detach the timer but only clear its function to NULL
if (base->running_timer != timer)
ret = detach_if_pending(timer, base, true);
if (shutdown)
timer->function = NULL;
unlock_timer_base()
[call_timer_fn exit]
lock_timer_base()
base->running_timer = NULL;
unlock_timer_base()
...
// Now timer is pending while its function set to NULL.
// next timer trigger
<SOFTIRQ>
expire_timers()
WARN_ON_ONCE(!fn) // hit
...
lock_timer_base()
// Now timer will detach
if (base->running_timer != timer)
ret = detach_if_pending(timer, base, true);
if (shutdown)
timer->function = NULL;
unlock_timer_base()
The problem is that timer_shutdown_sync() clears the timer function
regardless of whether the timer is currently running. This can leave a
pending timer with a NULL function pointer, which triggers the
WARN_ON_ONCE(!fn) check in expire_timers().
Fix this by only clearing the timer function when actually detaching the
timer. If the timer is running, leave the function pointer intact, which is
safe because the timer will be properly detached when it finishes running. |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: Fix proto fallback detection with BPF
The sockmap feature allows bpf syscall from userspace, or based
on bpf sockops, replacing the sk_prot of sockets during protocol stack
processing with sockmap's custom read/write interfaces.
'''
tcp_rcv_state_process()
syn_recv_sock()/subflow_syn_recv_sock()
tcp_init_transfer(BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB)
bpf_skops_established <== sockops
bpf_sock_map_update(sk) <== call bpf helper
tcp_bpf_update_proto() <== update sk_prot
'''
When the server has MPTCP enabled but the client sends a TCP SYN
without MPTCP, subflow_syn_recv_sock() performs a fallback on the
subflow, replacing the subflow sk's sk_prot with the native sk_prot.
'''
subflow_syn_recv_sock()
subflow_ulp_fallback()
subflow_drop_ctx()
mptcp_subflow_ops_undo_override()
'''
Then, this subflow can be normally used by sockmap, which replaces the
native sk_prot with sockmap's custom sk_prot. The issue occurs when the
user executes accept::mptcp_stream_accept::mptcp_fallback_tcp_ops().
Here, it uses sk->sk_prot to compare with the native sk_prot, but this
is incorrect when sockmap is used, as we may incorrectly set
sk->sk_socket->ops.
This fix uses the more generic sk_family for the comparison instead.
Additionally, this also prevents a WARNING from occurring:
result from ./scripts/decode_stacktrace.sh:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 337 at net/mptcp/protocol.c:68 mptcp_stream_accept \
(net/mptcp/protocol.c:4005)
Modules linked in:
...
PKRU: 55555554
Call Trace:
<TASK>
do_accept (net/socket.c:1989)
__sys_accept4 (net/socket.c:2028 net/socket.c:2057)
__x64_sys_accept (net/socket.c:2067)
x64_sys_call (arch/x86/entry/syscall_64.c:41)
do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
RIP: 0033:0x7f87ac92b83d
---[ end trace 0000000000000000 ]--- |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: target: tcm_loop: Fix segfault in tcm_loop_tpg_address_show()
If the allocation of tl_hba->sh fails in tcm_loop_driver_probe() and we
attempt to dereference it in tcm_loop_tpg_address_show() we will get a
segfault, see below for an example. So, check tl_hba->sh before
dereferencing it.
Unable to allocate struct scsi_host
BUG: kernel NULL pointer dereference, address: 0000000000000194
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 1 PID: 8356 Comm: tokio-runtime-w Not tainted 6.6.104.2-4.azl3 #1
Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 09/28/2024
RIP: 0010:tcm_loop_tpg_address_show+0x2e/0x50 [tcm_loop]
...
Call Trace:
<TASK>
configfs_read_iter+0x12d/0x1d0 [configfs]
vfs_read+0x1b5/0x300
ksys_read+0x6f/0xf0
... |
| In the Linux kernel, the following vulnerability has been resolved:
ipv4: route: Prevent rt_bind_exception() from rebinding stale fnhe
The sit driver's packet transmission path calls: sit_tunnel_xmit() ->
update_or_create_fnhe(), which lead to fnhe_remove_oldest() being called
to delete entries exceeding FNHE_RECLAIM_DEPTH+random.
The race window is between fnhe_remove_oldest() selecting fnheX for
deletion and the subsequent kfree_rcu(). During this time, the
concurrent path's __mkroute_output() -> find_exception() can fetch the
soon-to-be-deleted fnheX, and rt_bind_exception() then binds it with a
new dst using a dst_hold(). When the original fnheX is freed via RCU,
the dst reference remains permanently leaked.
CPU 0 CPU 1
__mkroute_output()
find_exception() [fnheX]
update_or_create_fnhe()
fnhe_remove_oldest() [fnheX]
rt_bind_exception() [bind dst]
RCU callback [fnheX freed, dst leak]
This issue manifests as a device reference count leak and a warning in
dmesg when unregistering the net device:
unregister_netdevice: waiting for sitX to become free. Usage count = N
Ido Schimmel provided the simple test validation method [1].
The fix clears 'oldest->fnhe_daddr' before calling fnhe_flush_routes().
Since rt_bind_exception() checks this field, setting it to zero prevents
the stale fnhe from being reused and bound to a new dst just before it
is freed.
[1]
ip netns add ns1
ip -n ns1 link set dev lo up
ip -n ns1 address add 192.0.2.1/32 dev lo
ip -n ns1 link add name dummy1 up type dummy
ip -n ns1 route add 192.0.2.2/32 dev dummy1
ip -n ns1 link add name gretap1 up arp off type gretap \
local 192.0.2.1 remote 192.0.2.2
ip -n ns1 route add 198.51.0.0/16 dev gretap1
taskset -c 0 ip netns exec ns1 mausezahn gretap1 \
-A 198.51.100.1 -B 198.51.0.0/16 -t udp -p 1000 -c 0 -q &
taskset -c 2 ip netns exec ns1 mausezahn gretap1 \
-A 198.51.100.1 -B 198.51.0.0/16 -t udp -p 1000 -c 0 -q &
sleep 10
ip netns pids ns1 | xargs kill
ip netns del ns1 |
| In the Linux kernel, the following vulnerability has been resolved:
net: atlantic: fix fragment overflow handling in RX path
The atlantic driver can receive packets with more than MAX_SKB_FRAGS (17)
fragments when handling large multi-descriptor packets. This causes an
out-of-bounds write in skb_add_rx_frag_netmem() leading to kernel panic.
The issue occurs because the driver doesn't check the total number of
fragments before calling skb_add_rx_frag(). When a packet requires more
than MAX_SKB_FRAGS fragments, the fragment index exceeds the array bounds.
Fix by assuming there will be an extra frag if buff->len > AQ_CFG_RX_HDR_SIZE,
then all fragments are accounted for. And reusing the existing check to
prevent the overflow earlier in the code path.
This crash occurred in production with an Aquantia AQC113 10G NIC.
Stack trace from production environment:
```
RIP: 0010:skb_add_rx_frag_netmem+0x29/0xd0
Code: 90 f3 0f 1e fa 0f 1f 44 00 00 48 89 f8 41 89
ca 48 89 d7 48 63 ce 8b 90 c0 00 00 00 48 c1 e1 04 48 01 ca 48 03 90
c8 00 00 00 <48> 89 7a 30 44 89 52 3c 44 89 42 38 40 f6 c7 01 75 74 48
89 fa 83
RSP: 0018:ffffa9bec02a8d50 EFLAGS: 00010287
RAX: ffff925b22e80a00 RBX: ffff925ad38d2700 RCX:
fffffffe0a0c8000
RDX: ffff9258ea95bac0 RSI: ffff925ae0a0c800 RDI:
0000000000037a40
RBP: 0000000000000024 R08: 0000000000000000 R09:
0000000000000021
R10: 0000000000000848 R11: 0000000000000000 R12:
ffffa9bec02a8e24
R13: ffff925ad8615570 R14: 0000000000000000 R15:
ffff925b22e80a00
FS: 0000000000000000(0000)
GS:ffff925e47880000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff9258ea95baf0 CR3: 0000000166022004 CR4:
0000000000f72ef0
PKRU: 55555554
Call Trace:
<IRQ>
aq_ring_rx_clean+0x175/0xe60 [atlantic]
? aq_ring_rx_clean+0x14d/0xe60 [atlantic]
? aq_ring_tx_clean+0xdf/0x190 [atlantic]
? kmem_cache_free+0x348/0x450
? aq_vec_poll+0x81/0x1d0 [atlantic]
? __napi_poll+0x28/0x1c0
? net_rx_action+0x337/0x420
```
Changes in v4:
- Add Fixes: tag to satisfy patch validation requirements.
Changes in v3:
- Fix by assuming there will be an extra frag if buff->len > AQ_CFG_RX_HDR_SIZE,
then all fragments are accounted for. |
| In the Linux kernel, the following vulnerability has been resolved:
ice: fix PTP cleanup on driver removal in error path
Improve the cleanup on releasing PTP resources in error path.
The error case might happen either at the driver probe and PTP
feature initialization or on PTP restart (errors in reset handling, NVM
update etc). In both cases, calls to PF PTP cleanup (ice_ptp_cleanup_pf
function) and 'ps_lock' mutex deinitialization were missed.
Additionally, ptp clock was not unregistered in the latter case.
Keep PTP state as 'uninitialized' on init to distinguish between error
scenarios and to avoid resource release duplication at driver removal.
The consequence of missing ice_ptp_cleanup_pf call is the following call
trace dumped when ice_adapter object is freed (port list is not empty,
as it is required at this stage):
[ T93022] ------------[ cut here ]------------
[ T93022] WARNING: CPU: 10 PID: 93022 at
ice/ice_adapter.c:67 ice_adapter_put+0xef/0x100 [ice]
...
[ T93022] RIP: 0010:ice_adapter_put+0xef/0x100 [ice]
...
[ T93022] Call Trace:
[ T93022] <TASK>
[ T93022] ? ice_adapter_put+0xef/0x100 [ice
33d2647ad4f6d866d41eefff1806df37c68aef0c]
[ T93022] ? __warn.cold+0xb0/0x10e
[ T93022] ? ice_adapter_put+0xef/0x100 [ice
33d2647ad4f6d866d41eefff1806df37c68aef0c]
[ T93022] ? report_bug+0xd8/0x150
[ T93022] ? handle_bug+0xe9/0x110
[ T93022] ? exc_invalid_op+0x17/0x70
[ T93022] ? asm_exc_invalid_op+0x1a/0x20
[ T93022] ? ice_adapter_put+0xef/0x100 [ice
33d2647ad4f6d866d41eefff1806df37c68aef0c]
[ T93022] pci_device_remove+0x42/0xb0
[ T93022] device_release_driver_internal+0x19f/0x200
[ T93022] driver_detach+0x48/0x90
[ T93022] bus_remove_driver+0x70/0xf0
[ T93022] pci_unregister_driver+0x42/0xb0
[ T93022] ice_module_exit+0x10/0xdb0 [ice
33d2647ad4f6d866d41eefff1806df37c68aef0c]
...
[ T93022] ---[ end trace 0000000000000000 ]---
[ T93022] ice: module unloaded |
| In the Linux kernel, the following vulnerability has been resolved:
afs: Fix delayed allocation of a cell's anonymous key
The allocation of a cell's anonymous key is done in a background thread
along with other cell setup such as doing a DNS upcall. In the reported
bug, this is triggered by afs_parse_source() parsing the device name given
to mount() and calling afs_lookup_cell() with the name of the cell.
The normal key lookup then tries to use the key description on the
anonymous authentication key as the reference for request_key() - but it
may not yet be set and so an oops can happen.
This has been made more likely to happen by the fix for dynamic lookup
failure.
Fix this by firstly allocating a reference name and attaching it to the
afs_cell record when the record is created. It can share the memory
allocation with the cell name (unfortunately it can't just overlap the cell
name by prepending it with "afs@" as the cell name already has a '.'
prepended for other purposes). This reference name is then passed to
request_key().
Secondly, the anon key is now allocated on demand at the point a key is
requested in afs_request_key() if it is not already allocated. A mutex is
used to prevent multiple allocation for a cell.
Thirdly, make afs_request_key_rcu() return NULL if the anonymous key isn't
yet allocated (if we need it) and then the caller can return -ECHILD to
drop out of RCU-mode and afs_request_key() can be called.
Note that the anonymous key is kind of necessary to make the key lookup
cache work as that doesn't currently cache a negative lookup, but it's
probably worth some investigation to see if NULL can be used instead. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: core: Fix invalid probe error return value
After DME Link Startup, the error return value is set to the MIPI UniPro
GenericErrorCode which can be 0 (SUCCESS) or 1 (FAILURE). Upon failure
during driver probe, the error code 1 is propagated back to the driver
probe function which must return a negative value to indicate an error,
but 1 is not negative, so the probe is considered to be successful even
though it failed. Subsequently, removing the driver results in an oops
because it is not in a valid state.
This happens because none of the callers of ufshcd_init() expect a
non-negative error code.
Fix the return value and documentation to match actual usage. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/msm: make sure last_fence is always updated
Update last_fence in the vm-bind path instead of kernel managed path.
last_fence is used to wait for work to finish in vm_bind contexts but not
used for kernel managed contexts.
This fixes a bug where last_fence is not waited on context close leading
to faults as resources are freed while in use.
Patchwork: https://patchwork.freedesktop.org/patch/680080/ |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btusb: mediatek: Fix kernel crash when releasing mtk iso interface
When performing reset tests and encountering abnormal card drop issues
that lead to a kernel crash, it is necessary to perform a null check
before releasing resources to avoid attempting to release a null pointer.
<4>[ 29.158070] Hardware name: Google Quigon sku196612/196613 board (DT)
<4>[ 29.158076] Workqueue: hci0 hci_cmd_sync_work [bluetooth]
<4>[ 29.158154] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
<4>[ 29.158162] pc : klist_remove+0x90/0x158
<4>[ 29.158174] lr : klist_remove+0x88/0x158
<4>[ 29.158180] sp : ffffffc0846b3c00
<4>[ 29.158185] pmr_save: 000000e0
<4>[ 29.158188] x29: ffffffc0846b3c30 x28: ffffff80cd31f880 x27: ffffff80c1bdc058
<4>[ 29.158199] x26: dead000000000100 x25: ffffffdbdc624ea3 x24: ffffff80c1bdc4c0
<4>[ 29.158209] x23: ffffffdbdc62a3e6 x22: ffffff80c6c07000 x21: ffffffdbdc829290
<4>[ 29.158219] x20: 0000000000000000 x19: ffffff80cd3e0648 x18: 000000031ec97781
<4>[ 29.158229] x17: ffffff80c1bdc4a8 x16: ffffffdc10576548 x15: ffffff80c1180428
<4>[ 29.158238] x14: 0000000000000000 x13: 000000000000e380 x12: 0000000000000018
<4>[ 29.158248] x11: ffffff80c2a7fd10 x10: 0000000000000000 x9 : 0000000100000000
<4>[ 29.158257] x8 : 0000000000000000 x7 : 7f7f7f7f7f7f7f7f x6 : 2d7223ff6364626d
<4>[ 29.158266] x5 : 0000008000000000 x4 : 0000000000000020 x3 : 2e7325006465636e
<4>[ 29.158275] x2 : ffffffdc11afeff8 x1 : 0000000000000000 x0 : ffffffdc11be4d0c
<4>[ 29.158285] Call trace:
<4>[ 29.158290] klist_remove+0x90/0x158
<4>[ 29.158298] device_release_driver_internal+0x20c/0x268
<4>[ 29.158308] device_release_driver+0x1c/0x30
<4>[ 29.158316] usb_driver_release_interface+0x70/0x88
<4>[ 29.158325] btusb_mtk_release_iso_intf+0x68/0xd8 [btusb (HASH:e8b6 5)]
<4>[ 29.158347] btusb_mtk_reset+0x5c/0x480 [btusb (HASH:e8b6 5)]
<4>[ 29.158361] hci_cmd_sync_work+0x10c/0x188 [bluetooth (HASH:a4fa 6)]
<4>[ 29.158430] process_scheduled_works+0x258/0x4e8
<4>[ 29.158441] worker_thread+0x300/0x428
<4>[ 29.158448] kthread+0x108/0x1d0
<4>[ 29.158455] ret_from_fork+0x10/0x20
<0>[ 29.158467] Code: 91343000 940139d1 f9400268 927ff914 (f9401297)
<4>[ 29.158474] ---[ end trace 0000000000000000 ]---
<0>[ 29.167129] Kernel panic - not syncing: Oops: Fatal exception
<2>[ 29.167144] SMP: stopping secondary CPUs
<4>[ 29.167158] ------------[ cut here ]------------ |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_core: lookup hci_conn on RX path on protocol side
The hdev lock/lookup/unlock/use pattern in the packet RX path doesn't
ensure hci_conn* is not concurrently modified/deleted. This locking
appears to be leftover from before conn_hash started using RCU
commit bf4c63252490b ("Bluetooth: convert conn hash to RCU")
and not clear if it had purpose since then.
Currently, there are code paths that delete hci_conn* from elsewhere
than the ordered hdev->workqueue where the RX work runs in. E.g.
commit 5af1f84ed13a ("Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync")
introduced some of these, and there probably were a few others before
it. It's better to do the locking so that even if these run
concurrently no UAF is possible.
Move the lookup of hci_conn and associated socket-specific conn to
protocol recv handlers, and do them within a single critical section
to cover hci_conn* usage and lookup.
syzkaller has reported a crash that appears to be this issue:
[Task hdev->workqueue] [Task 2]
hci_disconnect_all_sync
l2cap_recv_acldata(hcon)
hci_conn_get(hcon)
hci_abort_conn_sync(hcon)
hci_dev_lock
hci_dev_lock
hci_conn_del(hcon)
v-------------------------------- hci_dev_unlock
hci_conn_put(hcon)
conn = hcon->l2cap_data (UAF) |
| In the Linux kernel, the following vulnerability has been resolved:
net: sxgbe: fix potential NULL dereference in sxgbe_rx()
Currently, when skb is null, the driver prints an error and then
dereferences skb on the next line.
To fix this, let's add a 'break' after the error message to switch
to sxgbe_rx_refill(), which is similar to the approach taken by the
other drivers in this particular case, e.g. calxeda with xgmac_rx().
Found during a code review. |
| In the Linux kernel, the following vulnerability has been resolved:
fs/namespace: fix reference leak in grab_requested_mnt_ns
lookup_mnt_ns() already takes a reference on mnt_ns.
grab_requested_mnt_ns() doesn't need to take an extra reference. |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring/net: ensure vectored buffer node import is tied to notification
When support for vectored registered buffers was added, the import
itself is using 'req' rather than the notification io_kiocb, sr->notif.
For non-vectored imports, sr->notif is correctly used. This is important
as the lifetime of the two may be different. Use the correct io_kiocb
for the vectored buffer import. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/huge_memory: fix NULL pointer deference when splitting folio
Commit c010d47f107f ("mm: thp: split huge page to any lower order pages")
introduced an early check on the folio's order via mapping->flags before
proceeding with the split work.
This check introduced a bug: for shmem folios in the swap cache and
truncated folios, the mapping pointer can be NULL. Accessing
mapping->flags in this state leads directly to a NULL pointer dereference.
This commit fixes the issue by moving the check for mapping != NULL before
any attempt to access mapping->flags. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/memfd: fix information leak in hugetlb folios
When allocating hugetlb folios for memfd, three initialization steps are
missing:
1. Folios are not zeroed, leading to kernel memory disclosure to userspace
2. Folios are not marked uptodate before adding to page cache
3. hugetlb_fault_mutex is not taken before hugetlb_add_to_page_cache()
The memfd allocation path bypasses the normal page fault handler
(hugetlb_no_page) which would handle all of these initialization steps.
This is problematic especially for udmabuf use cases where folios are
pinned and directly accessed by userspace via DMA.
Fix by matching the initialization pattern used in hugetlb_no_page():
- Zero the folio using folio_zero_user() which is optimized for huge pages
- Mark it uptodate with folio_mark_uptodate()
- Take hugetlb_fault_mutex before adding to page cache to prevent races
The folio_zero_user() change also fixes a potential security issue where
uninitialized kernel memory could be disclosed to userspace through read()
or mmap() operations on the memfd. |
| In the Linux kernel, the following vulnerability has been resolved:
most: usb: fix double free on late probe failure
The MOST subsystem has a non-standard registration function which frees
the interface on registration failures and on deregistration.
This unsurprisingly leads to bugs in the MOST drivers, and a couple of
recent changes turned a reference underflow and use-after-free in the
USB driver into several double free and a use-after-free on late probe
failures. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_eem: Fix memory leak in eem_unwrap
The existing code did not handle the failure case of usb_ep_queue in the
command path, potentially leading to memory leaks.
Improve error handling to free all allocated resources on usb_ep_queue
failure. This patch continues to use goto logic for error handling, as the
existing error handling is complex and not easily adaptable to auto-cleanup
helpers.
kmemleak results:
unreferenced object 0xffffff895a512300 (size 240):
backtrace:
slab_post_alloc_hook+0xbc/0x3a4
kmem_cache_alloc+0x1b4/0x358
skb_clone+0x90/0xd8
eem_unwrap+0x1cc/0x36c
unreferenced object 0xffffff8a157f4000 (size 256):
backtrace:
slab_post_alloc_hook+0xbc/0x3a4
__kmem_cache_alloc_node+0x1b4/0x2dc
kmalloc_trace+0x48/0x140
dwc3_gadget_ep_alloc_request+0x58/0x11c
usb_ep_alloc_request+0x40/0xe4
eem_unwrap+0x204/0x36c
unreferenced object 0xffffff8aadbaac00 (size 128):
backtrace:
slab_post_alloc_hook+0xbc/0x3a4
__kmem_cache_alloc_node+0x1b4/0x2dc
__kmalloc+0x64/0x1a8
eem_unwrap+0x218/0x36c
unreferenced object 0xffffff89ccef3500 (size 64):
backtrace:
slab_post_alloc_hook+0xbc/0x3a4
__kmem_cache_alloc_node+0x1b4/0x2dc
kmalloc_trace+0x48/0x140
eem_unwrap+0x238/0x36c |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: zstd - fix double-free in per-CPU stream cleanup
The crypto/zstd module has a double-free bug that occurs when multiple
tfms are allocated and freed.
The issue happens because zstd_streams (per-CPU contexts) are freed in
zstd_exit() during every tfm destruction, rather than being managed at
the module level. When multiple tfms exist, each tfm exit attempts to
free the same shared per-CPU streams, resulting in a double-free.
This leads to a stack trace similar to:
BUG: Bad page state in process kworker/u16:1 pfn:106fd93
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x106fd93
flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff)
page_type: 0xffffffff()
raw: 0017ffffc0000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: nonzero entire_mapcount
Modules linked in: ...
CPU: 3 UID: 0 PID: 2506 Comm: kworker/u16:1 Kdump: loaded Tainted: G B
Hardware name: ...
Workqueue: btrfs-delalloc btrfs_work_helper
Call Trace:
<TASK>
dump_stack_lvl+0x5d/0x80
bad_page+0x71/0xd0
free_unref_page_prepare+0x24e/0x490
free_unref_page+0x60/0x170
crypto_acomp_free_streams+0x5d/0xc0
crypto_acomp_exit_tfm+0x23/0x50
crypto_destroy_tfm+0x60/0xc0
...
Change the lifecycle management of zstd_streams to free the streams only
once during module cleanup. |
