Linux: >> Linux Kernel >> 4.14.334 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
sound/virtio: Fix cancel_sync warnings on uninitialized work_structs
Betty reported hitting the following warning:
[ 8.709131][ T221] WARNING: CPU: 2 PID: 221 at kernel/workqueue.c:4182
...
[ 8.713282][ T221] Call trace:
[ 8.713365][ T221] __flush_work+0x8d0/0x914
[ 8.713468][ T221] __cancel_work_sync+0xac/0xfc
[ 8.713570][ T221] cancel_work_sync+0x24/0x34
[ 8.713667][ T221] virtsnd_remove+0xa8/0xf8 [virtio_snd ab15f34d0dd772f6d11327e08a81d46dc9c36276]
[ 8.713868][ T221] virtsnd_probe+0x48c/0x664 [virtio_snd ab15f34d0dd772f6d11327e08a81d46dc9c36276]
[ 8.714035][ T221] virtio_dev_probe+0x28c/0x390
[ 8.714139][ T221] really_probe+0x1bc/0x4c8
...
It seems we're hitting the error path in virtsnd_probe(), which
triggers a virtsnd_remove() which iterates over the substreams
calling cancel_work_sync() on the elapsed_period work_struct.
Looking at the code, from earlier in:
virtsnd_probe()->virtsnd_build_devs()->virtsnd_pcm_parse_cfg()
We set snd->nsubstreams, allocate the snd->substreams, and if
we then hit an error on the info allocation or something in
virtsnd_ctl_query_info() fails, we will exit without having
initialized the elapsed_period work_struct.
When that error path unwinds we then call virtsnd_remove()
which as long as the substreams array is allocated, will iterate
through calling cancel_work_sync() on the uninitialized work
struct hitting this warning.
Takashi Iwai suggested this fix, which initializes the substreams
structure right after allocation, so that if we hit the error
paths we avoid trying to cleanup uninitialized data.
Note: I have not yet managed to reproduce the issue myself, so
this patch has had limited testing.
Feedback or thoughts would be appreciated!
CVSS Score
5.5
EPSS Score
0.001
Published
2025-05-08
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix kmemleak warning for percpu hashmap
Vlad Poenaru reported the following kmemleak issue:
unreferenced object 0x606fd7c44ac8 (size 32):
backtrace (crc 0):
pcpu_alloc_noprof+0x730/0xeb0
bpf_map_alloc_percpu+0x69/0xc0
prealloc_init+0x9d/0x1b0
htab_map_alloc+0x363/0x510
map_create+0x215/0x3a0
__sys_bpf+0x16b/0x3e0
__x64_sys_bpf+0x18/0x20
do_syscall_64+0x7b/0x150
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Further investigation shows the reason is due to not 8-byte aligned
store of percpu pointer in htab_elem_set_ptr():
*(void __percpu **)(l->key + key_size) = pptr;
Note that the whole htab_elem alignment is 8 (for x86_64). If the key_size
is 4, that means pptr is stored in a location which is 4 byte aligned but
not 8 byte aligned. In mm/kmemleak.c, scan_block() scans the memory based
on 8 byte stride, so it won't detect above pptr, hence reporting the memory
leak.
In htab_map_alloc(), we already have
htab->elem_size = sizeof(struct htab_elem) +
round_up(htab->map.key_size, 8);
if (percpu)
htab->elem_size += sizeof(void *);
else
htab->elem_size += round_up(htab->map.value_size, 8);
So storing pptr with 8-byte alignment won't cause any problem and can fix
kmemleak too.
The issue can be reproduced with bpf selftest as well:
1. Enable CONFIG_DEBUG_KMEMLEAK config
2. Add a getchar() before skel destroy in test_hash_map() in prog_tests/for_each.c.
The purpose is to keep map available so kmemleak can be detected.
3. run './test_progs -t for_each/hash_map &' and a kmemleak should be reported.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-05-08
In the Linux kernel, the following vulnerability has been resolved:
crypto: null - Use spin lock instead of mutex
As the null algorithm may be freed in softirq context through
af_alg, use spin locks instead of mutexes to protect the default
null algorithm.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-05-08
In the Linux kernel, the following vulnerability has been resolved:
driver core: fix potential NULL pointer dereference in dev_uevent()
If userspace reads "uevent" device attribute at the same time as another
threads unbinds the device from its driver, change to dev->driver from a
valid pointer to NULL may result in crash. Fix this by using READ_ONCE()
when fetching the pointer, and take bus' drivers klist lock to make sure
driver instance will not disappear while we access it.
Use WRITE_ONCE() when setting the driver pointer to ensure there is no
tearing.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-05-08
In the Linux kernel, the following vulnerability has been resolved:
scsi: target: Fix WRITE_SAME No Data Buffer crash
In newer version of the SBC specs, we have a NDOB bit that indicates there
is no data buffer that gets written out. If this bit is set using commands
like "sg_write_same --ndob" we will crash in target_core_iblock/file's
execute_write_same handlers when we go to access the se_cmd->t_data_sg
because its NULL.
This patch adds a check for the NDOB bit in the common WRITE SAME code
because we don't support it. And, it adds a check for zero SG elements in
each handler in case the initiator tries to send a normal WRITE SAME with
no data buffer.
CVSS Score
7.8
EPSS Score
0.001
Published
2025-05-02
In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: Fix a server shutdown leak
Fix a race where kthread_stop() may prevent the threadfn from ever getting
called. If that happens the svc_rqst will not be cleaned up.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-05-02
In the Linux kernel, the following vulnerability has been resolved:
scsi: core: Remove the /proc/scsi/${proc_name} directory earlier
Remove the /proc/scsi/${proc_name} directory earlier to fix a race
condition between unloading and reloading kernel modules. This fixes a bug
introduced in 2009 by commit 77c019768f06 ("[SCSI] fix /proc memory leak in
the SCSI core").
Fix the following kernel warning:
proc_dir_entry 'scsi/scsi_debug' already registered
WARNING: CPU: 19 PID: 27986 at fs/proc/generic.c:376 proc_register+0x27d/0x2e0
Call Trace:
proc_mkdir+0xb5/0xe0
scsi_proc_hostdir_add+0xb5/0x170
scsi_host_alloc+0x683/0x6c0
sdebug_driver_probe+0x6b/0x2d0 [scsi_debug]
really_probe+0x159/0x540
__driver_probe_device+0xdc/0x230
driver_probe_device+0x4f/0x120
__device_attach_driver+0xef/0x180
bus_for_each_drv+0xe5/0x130
__device_attach+0x127/0x290
device_initial_probe+0x17/0x20
bus_probe_device+0x110/0x130
device_add+0x673/0xc80
device_register+0x1e/0x30
sdebug_add_host_helper+0x1a7/0x3b0 [scsi_debug]
scsi_debug_init+0x64f/0x1000 [scsi_debug]
do_one_initcall+0xd7/0x470
do_init_module+0xe7/0x330
load_module+0x122a/0x12c0
__do_sys_finit_module+0x124/0x1a0
__x64_sys_finit_module+0x46/0x50
do_syscall_64+0x38/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
CVSS Score
5.5
EPSS Score
0.001
Published
2025-05-02
In the Linux kernel, the following vulnerability has been resolved:
loop: Fix use-after-free issues
do_req_filebacked() calls blk_mq_complete_request() synchronously or
asynchronously when using asynchronous I/O unless memory allocation fails.
Hence, modify loop_handle_cmd() such that it does not dereference 'cmd' nor
'rq' after do_req_filebacked() finished unless we are sure that the request
has not yet been completed. This patch fixes the following kernel crash:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000054
Call trace:
css_put.42938+0x1c/0x1ac
loop_process_work+0xc8c/0xfd4
loop_rootcg_workfn+0x24/0x34
process_one_work+0x244/0x558
worker_thread+0x400/0x8fc
kthread+0x16c/0x1e0
ret_from_fork+0x10/0x20
CVSS Score
7.8
EPSS Score
0.001
Published
2025-05-02
In the Linux kernel, the following vulnerability has been resolved:
bonding: restore bond's IFF_SLAVE flag if a non-eth dev enslave fails
syzbot reported a warning[1] where the bond device itself is a slave and
we try to enslave a non-ethernet device as the first slave which fails
but then in the error path when ether_setup() restores the bond device
it also clears all flags. In my previous fix[2] I restored the
IFF_MASTER flag, but I didn't consider the case that the bond device
itself might also be a slave with IFF_SLAVE set, so we need to restore
that flag as well. Use the bond_ether_setup helper which does the right
thing and restores the bond's flags properly.
Steps to reproduce using a nlmon dev:
$ ip l add nlmon0 type nlmon
$ ip l add bond1 type bond
$ ip l add bond2 type bond
$ ip l set bond1 master bond2
$ ip l set dev nlmon0 master bond1
$ ip -d l sh dev bond1
22: bond1: <BROADCAST,MULTICAST,MASTER> mtu 1500 qdisc noqueue master bond2 state DOWN mode DEFAULT group default qlen 1000
(now bond1's IFF_SLAVE flag is gone and we'll hit a warning[3] if we
try to delete it)
[1] https://syzkaller.appspot.com/bug?id=391c7b1f6522182899efba27d891f1743e8eb3ef
[2] commit 7d5cd2ce5292 ("bonding: correctly handle bonding type change on enslave failure")
[3] example warning:
[ 27.008664] bond1: (slave nlmon0): The slave device specified does not support setting the MAC address
[ 27.008692] bond1: (slave nlmon0): Error -95 calling set_mac_address
[ 32.464639] bond1 (unregistering): Released all slaves
[ 32.464685] ------------[ cut here ]------------
[ 32.464686] WARNING: CPU: 1 PID: 2004 at net/core/dev.c:10829 unregister_netdevice_many+0x72a/0x780
[ 32.464694] Modules linked in: br_netfilter bridge bonding virtio_net
[ 32.464699] CPU: 1 PID: 2004 Comm: ip Kdump: loaded Not tainted 5.18.0-rc3+ #47
[ 32.464703] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.1-2.fc37 04/01/2014
[ 32.464704] RIP: 0010:unregister_netdevice_many+0x72a/0x780
[ 32.464707] Code: 99 fd ff ff ba 90 1a 00 00 48 c7 c6 f4 02 66 96 48 c7 c7 20 4d 35 96 c6 05 fa c7 2b 02 01 e8 be 6f 4a 00 0f 0b e9 73 fd ff ff <0f> 0b e9 5f fd ff ff 80 3d e3 c7 2b 02 00 0f 85 3b fd ff ff ba 59
[ 32.464710] RSP: 0018:ffffa006422d7820 EFLAGS: 00010206
[ 32.464712] RAX: ffff8f6e077140a0 RBX: ffffa006422d7888 RCX: 0000000000000000
[ 32.464714] RDX: ffff8f6e12edbe58 RSI: 0000000000000296 RDI: ffffffff96d4a520
[ 32.464716] RBP: ffff8f6e07714000 R08: ffffffff96d63600 R09: ffffa006422d7728
[ 32.464717] R10: 0000000000000ec0 R11: ffffffff9698c988 R12: ffff8f6e12edb140
[ 32.464719] R13: dead000000000122 R14: dead000000000100 R15: ffff8f6e12edb140
[ 32.464723] FS: 00007f297c2f1740(0000) GS:ffff8f6e5d900000(0000) knlGS:0000000000000000
[ 32.464725] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 32.464726] CR2: 00007f297bf1c800 CR3: 00000000115e8000 CR4: 0000000000350ee0
[ 32.464730] Call Trace:
[ 32.464763] <TASK>
[ 32.464767] rtnl_dellink+0x13e/0x380
[ 32.464776] ? cred_has_capability.isra.0+0x68/0x100
[ 32.464780] ? __rtnl_unlock+0x33/0x60
[ 32.464783] ? bpf_lsm_capset+0x10/0x10
[ 32.464786] ? security_capable+0x36/0x50
[ 32.464790] rtnetlink_rcv_msg+0x14e/0x3b0
[ 32.464792] ? _copy_to_iter+0xb1/0x790
[ 32.464796] ? post_alloc_hook+0xa0/0x160
[ 32.464799] ? rtnl_calcit.isra.0+0x110/0x110
[ 32.464802] netlink_rcv_skb+0x50/0xf0
[ 32.464806] netlink_unicast+0x216/0x340
[ 32.464809] netlink_sendmsg+0x23f/0x480
[ 32.464812] sock_sendmsg+0x5e/0x60
[ 32.464815] ____sys_sendmsg+0x22c/0x270
[ 32.464818] ? import_iovec+0x17/0x20
[ 32.464821] ? sendmsg_copy_msghdr+0x59/0x90
[ 32.464823] ? do_set_pte+0xa0/0xe0
[ 32.464828] ___sys_sendmsg+0x81/0xc0
[ 32.464832] ? mod_objcg_state+0xc6/0x300
[ 32.464835] ? refill_obj_stock+0xa9/0x160
[ 32.464838] ? memcg_slab_free_hook+0x1a5/0x1f0
[ 32.464842] __sys_sendm
---truncated---
CVSS Score
5.5
EPSS Score
0.001
Published
2025-05-02
In the Linux kernel, the following vulnerability has been resolved:
ext4: update s_journal_inum if it changes after journal replay
When mounting a crafted ext4 image, s_journal_inum may change after journal
replay, which is obviously unreasonable because we have successfully loaded
and replayed the journal through the old s_journal_inum. And the new
s_journal_inum bypasses some of the checks in ext4_get_journal(), which
may trigger a null pointer dereference problem. So if s_journal_inum
changes after the journal replay, we ignore the change, and rewrite the
current journal_inum to the superblock.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-05-02