Linux: >> Linux Kernel >> 2.6.25.16 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
PM: hibernate: defer device probing when resuming from hibernation
syzbot is reporting hung task at misc_open() [1], for there is a race
window of AB-BA deadlock which involves probe_count variable. Currently
wait_for_device_probe() from snapshot_open() from misc_open() can sleep
forever with misc_mtx held if probe_count cannot become 0.
When a device is probed by hub_event() work function, probe_count is
incremented before the probe function starts, and probe_count is
decremented after the probe function completed.
There are three cases that can prevent probe_count from dropping to 0.
(a) A device being probed stopped responding (i.e. broken/malicious
hardware).
(b) A process emulating a USB device using /dev/raw-gadget interface
stopped responding for some reason.
(c) New device probe requests keeps coming in before existing device
probe requests complete.
The phenomenon syzbot is reporting is (b). A process which is holding
system_transition_mutex and misc_mtx is waiting for probe_count to become
0 inside wait_for_device_probe(), but the probe function which is called
from hub_event() work function is waiting for the processes which are
blocked at mutex_lock(&misc_mtx) to respond via /dev/raw-gadget interface.
This patch mitigates (b) by deferring wait_for_device_probe() from
snapshot_open() to snapshot_write() and snapshot_ioctl(). Please note that
the possibility of (b) remains as long as any thread which is emulating a
USB device via /dev/raw-gadget interface can be blocked by uninterruptible
blocking operations (e.g. mutex_lock()).
Please also note that (a) and (c) are not addressed. Regarding (c), we
should change the code to wait for only one device which contains the
image for resuming from hibernation. I don't know how to address (a), for
use of timeout for wait_for_device_probe() might result in loss of user
data in the image. Maybe we should require the userland to wait for the
image device before opening /dev/snapshot interface.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
jbd2: fix assertion 'jh->b_frozen_data == NULL' failure when journal aborted
Following process will fail assertion 'jh->b_frozen_data == NULL' in
jbd2_journal_dirty_metadata():
jbd2_journal_commit_transaction
unlink(dir/a)
jh->b_transaction = trans1
jh->b_jlist = BJ_Metadata
journal->j_running_transaction = NULL
trans1->t_state = T_COMMIT
unlink(dir/b)
handle->h_trans = trans2
do_get_write_access
jh->b_modified = 0
jh->b_frozen_data = frozen_buffer
jh->b_next_transaction = trans2
jbd2_journal_dirty_metadata
is_handle_aborted
is_journal_aborted // return false
--> jbd2 abort <--
while (commit_transaction->t_buffers)
if (is_journal_aborted)
jbd2_journal_refile_buffer
__jbd2_journal_refile_buffer
WRITE_ONCE(jh->b_transaction,
jh->b_next_transaction)
WRITE_ONCE(jh->b_next_transaction, NULL)
__jbd2_journal_file_buffer(jh, BJ_Reserved)
J_ASSERT_JH(jh, jh->b_frozen_data == NULL) // assertion failure !
The reproducer (See detail in [Link]) reports:
------------[ cut here ]------------
kernel BUG at fs/jbd2/transaction.c:1629!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU: 2 PID: 584 Comm: unlink Tainted: G W
5.19.0-rc6-00115-g4a57a8400075-dirty #697
RIP: 0010:jbd2_journal_dirty_metadata+0x3c5/0x470
RSP: 0018:ffffc90000be7ce0 EFLAGS: 00010202
Call Trace:
<TASK>
__ext4_handle_dirty_metadata+0xa0/0x290
ext4_handle_dirty_dirblock+0x10c/0x1d0
ext4_delete_entry+0x104/0x200
__ext4_unlink+0x22b/0x360
ext4_unlink+0x275/0x390
vfs_unlink+0x20b/0x4c0
do_unlinkat+0x42f/0x4c0
__x64_sys_unlink+0x37/0x50
do_syscall_64+0x35/0x80
After journal aborting, __jbd2_journal_refile_buffer() is executed with
holding @jh->b_state_lock, we can fix it by moving 'is_handle_aborted()'
into the area protected by @jh->b_state_lock.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
powerpc/cell/axon_msi: Fix refcount leak in setup_msi_msg_address
of_get_next_parent() returns a node pointer with refcount incremented,
we should use of_node_put() on it when not need anymore.
Add missing of_node_put() in the error path to avoid refcount leak.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
video: fbdev: arkfb: Check the size of screen before memset_io()
In the function arkfb_set_par(), the value of 'screen_size' is
calculated by the user input. If the user provides the improper value,
the value of 'screen_size' may larger than 'info->screen_size', which
may cause the following bug:
[ 659.399066] BUG: unable to handle page fault for address: ffffc90003000000
[ 659.399077] #PF: supervisor write access in kernel mode
[ 659.399079] #PF: error_code(0x0002) - not-present page
[ 659.399094] RIP: 0010:memset_orig+0x33/0xb0
[ 659.399116] Call Trace:
[ 659.399122] arkfb_set_par+0x143f/0x24c0
[ 659.399130] fb_set_var+0x604/0xeb0
[ 659.399161] do_fb_ioctl+0x234/0x670
[ 659.399189] fb_ioctl+0xdd/0x130
Fix the this by checking the value of 'screen_size' before memset_io().
CVSS Score
7.8
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
video: fbdev: vt8623fb: Check the size of screen before memset_io()
In the function vt8623fb_set_par(), the value of 'screen_size' is
calculated by the user input. If the user provides the improper value,
the value of 'screen_size' may larger than 'info->screen_size', which
may cause the following bug:
[ 583.339036] BUG: unable to handle page fault for address: ffffc90005000000
[ 583.339049] #PF: supervisor write access in kernel mode
[ 583.339052] #PF: error_code(0x0002) - not-present page
[ 583.339074] RIP: 0010:memset_orig+0x33/0xb0
[ 583.339110] Call Trace:
[ 583.339118] vt8623fb_set_par+0x11cd/0x21e0
[ 583.339146] fb_set_var+0x604/0xeb0
[ 583.339181] do_fb_ioctl+0x234/0x670
[ 583.339209] fb_ioctl+0xdd/0x130
Fix the this by checking the value of 'screen_size' before memset_io().
CVSS Score
7.8
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
video: fbdev: arkfb: Fix a divide-by-zero bug in ark_set_pixclock()
Since the user can control the arguments of the ioctl() from the user
space, under special arguments that may result in a divide-by-zero bug
in:
drivers/video/fbdev/arkfb.c:784: ark_set_pixclock(info, (hdiv * info->var.pixclock) / hmul);
with hdiv=1, pixclock=1 and hmul=2 you end up with (1*1)/2 = (int) 0.
and then in:
drivers/video/fbdev/arkfb.c:504: rv = dac_set_freq(par->dac, 0, 1000000000 / pixclock);
we'll get a division-by-zero.
The following log can reveal it:
divide error: 0000 [#1] PREEMPT SMP KASAN PTI
RIP: 0010:ark_set_pixclock drivers/video/fbdev/arkfb.c:504 [inline]
RIP: 0010:arkfb_set_par+0x10fc/0x24c0 drivers/video/fbdev/arkfb.c:784
Call Trace:
fb_set_var+0x604/0xeb0 drivers/video/fbdev/core/fbmem.c:1034
do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1110
fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1189
Fix this by checking the argument of ark_set_pixclock() first.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
powerpc/spufs: Fix refcount leak in spufs_init_isolated_loader
of_find_node_by_path() returns remote device nodepointer with
refcount incremented, we should use of_node_put() on it when done.
Add missing of_node_put() to avoid refcount leak.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
video: fbdev: s3fb: Check the size of screen before memset_io()
In the function s3fb_set_par(), the value of 'screen_size' is
calculated by the user input. If the user provides the improper value,
the value of 'screen_size' may larger than 'info->screen_size', which
may cause the following bug:
[ 54.083733] BUG: unable to handle page fault for address: ffffc90003000000
[ 54.083742] #PF: supervisor write access in kernel mode
[ 54.083744] #PF: error_code(0x0002) - not-present page
[ 54.083760] RIP: 0010:memset_orig+0x33/0xb0
[ 54.083782] Call Trace:
[ 54.083788] s3fb_set_par+0x1ec6/0x4040
[ 54.083806] fb_set_var+0x604/0xeb0
[ 54.083836] do_fb_ioctl+0x234/0x670
Fix the this by checking the value of 'screen_size' before memset_io().
CVSS Score
7.8
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix warning in ext4_iomap_begin as race between bmap and write
We got issue as follows:
------------[ cut here ]------------
WARNING: CPU: 3 PID: 9310 at fs/ext4/inode.c:3441 ext4_iomap_begin+0x182/0x5d0
RIP: 0010:ext4_iomap_begin+0x182/0x5d0
RSP: 0018:ffff88812460fa08 EFLAGS: 00010293
RAX: ffff88811f168000 RBX: 0000000000000000 RCX: ffffffff97793c12
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: ffff88812c669160 R08: ffff88811f168000 R09: ffffed10258cd20f
R10: ffff88812c669077 R11: ffffed10258cd20e R12: 0000000000000001
R13: 00000000000000a4 R14: 000000000000000c R15: ffff88812c6691ee
FS: 00007fd0d6ff3740(0000) GS:ffff8883af180000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd0d6dda290 CR3: 0000000104a62000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
iomap_apply+0x119/0x570
iomap_bmap+0x124/0x150
ext4_bmap+0x14f/0x250
bmap+0x55/0x80
do_vfs_ioctl+0x952/0xbd0
__x64_sys_ioctl+0xc6/0x170
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Above issue may happen as follows:
bmap write
bmap
ext4_bmap
iomap_bmap
ext4_iomap_begin
ext4_file_write_iter
ext4_buffered_write_iter
generic_perform_write
ext4_da_write_begin
ext4_da_write_inline_data_begin
ext4_prepare_inline_data
ext4_create_inline_data
ext4_set_inode_flag(inode,
EXT4_INODE_INLINE_DATA);
if (WARN_ON_ONCE(ext4_has_inline_data(inode))) ->trigger bug_on
To solved above issue hold inode lock in ext4_bamp.
CVSS Score
7.0
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
dm raid: fix address sanitizer warning in raid_status
There is this warning when using a kernel with the address sanitizer
and running this testsuite:
https://gitlab.com/cki-project/kernel-tests/-/tree/main/storage/swraid/scsi_raid
==================================================================
BUG: KASAN: slab-out-of-bounds in raid_status+0x1747/0x2820 [dm_raid]
Read of size 4 at addr ffff888079d2c7e8 by task lvcreate/13319
CPU: 0 PID: 13319 Comm: lvcreate Not tainted 5.18.0-0.rc3.<snip> #1
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
Call Trace:
<TASK>
dump_stack_lvl+0x6a/0x9c
print_address_description.constprop.0+0x1f/0x1e0
print_report.cold+0x55/0x244
kasan_report+0xc9/0x100
raid_status+0x1747/0x2820 [dm_raid]
dm_ima_measure_on_table_load+0x4b8/0xca0 [dm_mod]
table_load+0x35c/0x630 [dm_mod]
ctl_ioctl+0x411/0x630 [dm_mod]
dm_ctl_ioctl+0xa/0x10 [dm_mod]
__x64_sys_ioctl+0x12a/0x1a0
do_syscall_64+0x5b/0x80
The warning is caused by reading conf->max_nr_stripes in raid_status. The
code in raid_status reads mddev->private, casts it to struct r5conf and
reads the entry max_nr_stripes.
However, if we have different raid type than 4/5/6, mddev->private
doesn't point to struct r5conf; it may point to struct r0conf, struct
r1conf, struct r10conf or struct mpconf. If we cast a pointer to one
of these structs to struct r5conf, we will be reading invalid memory
and KASAN warns about it.
Fix this bug by reading struct r5conf only if raid type is 4, 5 or 6.
CVSS Score
7.1
EPSS Score
0.0
Published
2025-06-18