Linux: >> Linux Kernel >> 3.18.41 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
media: staging: media: zoran: move videodev alloc
Move some code out of zr36057_init() and create new functions for handling
zr->video_dev. This permit to ease code reading and fix a zr->video_dev
memory leak.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
media: staging: media: zoran: calculate the right buffer number for zoran_reap_stat_com
On the case tmp_dcim=1, the index of buffer is miscalculated.
This generate a NULL pointer dereference later.
So let's fix the calcul and add a check to prevent this to reappear.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
Revert "Revert "block, bfq: honor already-setup queue merges""
A crash [1] happened to be triggered in conjunction with commit
2d52c58b9c9b ("block, bfq: honor already-setup queue merges"). The
latter was then reverted by commit ebc69e897e17 ("Revert "block, bfq:
honor already-setup queue merges""). Yet, the reverted commit was not
the one introducing the bug. In fact, it actually triggered a UAF
introduced by a different commit, and now fixed by commit d29bd41428cf
("block, bfq: reset last_bfqq_created on group change").
So, there is no point in keeping commit 2d52c58b9c9b ("block, bfq:
honor already-setup queue merges") out. This commit restores it.
[1] https://bugzilla.kernel.org/show_bug.cgi?id=214503
CVSS Score
7.8
EPSS Score
0.001
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
video: fbdev: smscufx: Fix null-ptr-deref in ufx_usb_probe()
I got a null-ptr-deref report:
BUG: kernel NULL pointer dereference, address: 0000000000000000
...
RIP: 0010:fb_destroy_modelist+0x38/0x100
...
Call Trace:
ufx_usb_probe.cold+0x2b5/0xac1 [smscufx]
usb_probe_interface+0x1aa/0x3c0 [usbcore]
really_probe+0x167/0x460
...
ret_from_fork+0x1f/0x30
If fb_alloc_cmap() fails in ufx_usb_probe(), fb_destroy_modelist() will
be called to destroy modelist in the error handling path. But modelist
has not been initialized yet, so it will result in null-ptr-deref.
Initialize modelist before calling fb_alloc_cmap() to fix this bug.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
ath5k: fix OOB in ath5k_eeprom_read_pcal_info_5111
The bug was found during fuzzing. Stacktrace locates it in
ath5k_eeprom_convert_pcal_info_5111.
When none of the curve is selected in the loop, idx can go
up to AR5K_EEPROM_N_PD_CURVES. The line makes pd out of bound.
pd = &chinfo[pier].pd_curves[idx];
There are many OOB writes using pd later in the code. So I
added a sanity check for idx. Checks for other loops involving
AR5K_EEPROM_N_PD_CURVES are not needed as the loop index is not
used outside the loops.
The patch is NOT tested with real device.
The following is the fuzzing report
BUG: KASAN: slab-out-of-bounds in ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k]
Write of size 1 at addr ffff8880174a4d60 by task modprobe/214
CPU: 0 PID: 214 Comm: modprobe Not tainted 5.6.0 #1
Call Trace:
dump_stack+0x76/0xa0
print_address_description.constprop.0+0x16/0x200
? ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k]
? ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k]
__kasan_report.cold+0x37/0x7c
? ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k]
kasan_report+0xe/0x20
ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k]
? apic_timer_interrupt+0xa/0x20
? ath5k_eeprom_init_11a_pcal_freq+0xbc0/0xbc0 [ath5k]
? ath5k_pci_eeprom_read+0x228/0x3c0 [ath5k]
ath5k_eeprom_init+0x2513/0x6290 [ath5k]
? ath5k_eeprom_init_11a_pcal_freq+0xbc0/0xbc0 [ath5k]
? usleep_range+0xb8/0x100
? apic_timer_interrupt+0xa/0x20
? ath5k_eeprom_read_pcal_info_2413+0x2f20/0x2f20 [ath5k]
ath5k_hw_init+0xb60/0x1970 [ath5k]
ath5k_init_ah+0x6fe/0x2530 [ath5k]
? kasprintf+0xa6/0xe0
? ath5k_stop+0x140/0x140 [ath5k]
? _dev_notice+0xf6/0xf6
? apic_timer_interrupt+0xa/0x20
ath5k_pci_probe.cold+0x29a/0x3d6 [ath5k]
? ath5k_pci_eeprom_read+0x3c0/0x3c0 [ath5k]
? mutex_lock+0x89/0xd0
? ath5k_pci_eeprom_read+0x3c0/0x3c0 [ath5k]
local_pci_probe+0xd3/0x160
pci_device_probe+0x23f/0x3e0
? pci_device_remove+0x280/0x280
? pci_device_remove+0x280/0x280
really_probe+0x209/0x5d0
CVSS Score
7.1
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
ubi: Fix race condition between ctrl_cdev_ioctl and ubi_cdev_ioctl
Hulk Robot reported a KASAN report about use-after-free:
==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0x13d/0x160
Read of size 8 at addr ffff888035e37d98 by task ubiattach/1385
[...]
Call Trace:
klist_dec_and_del+0xa7/0x4a0
klist_put+0xc7/0x1a0
device_del+0x4d4/0xed0
cdev_device_del+0x1a/0x80
ubi_attach_mtd_dev+0x2951/0x34b0 [ubi]
ctrl_cdev_ioctl+0x286/0x2f0 [ubi]
Allocated by task 1414:
device_add+0x60a/0x18b0
cdev_device_add+0x103/0x170
ubi_create_volume+0x1118/0x1a10 [ubi]
ubi_cdev_ioctl+0xb7f/0x1ba0 [ubi]
Freed by task 1385:
cdev_device_del+0x1a/0x80
ubi_remove_volume+0x438/0x6c0 [ubi]
ubi_cdev_ioctl+0xbf4/0x1ba0 [ubi]
[...]
==================================================================
The lock held by ctrl_cdev_ioctl is ubi_devices_mutex, but the lock held
by ubi_cdev_ioctl is ubi->device_mutex. Therefore, the two locks can be
concurrent.
ctrl_cdev_ioctl contains two operations: ubi_attach and ubi_detach.
ubi_detach is bug-free because it uses reference counting to prevent
concurrency. However, uif_init and uif_close in ubi_attach may race with
ubi_cdev_ioctl.
uif_init will race with ubi_cdev_ioctl as in the following stack.
cpu1 cpu2 cpu3
_______________________|________________________|______________________
ctrl_cdev_ioctl
ubi_attach_mtd_dev
uif_init
ubi_cdev_ioctl
ubi_create_volume
cdev_device_add
ubi_add_volume
// sysfs exist
kill_volumes
ubi_cdev_ioctl
ubi_remove_volume
cdev_device_del
// first free
ubi_free_volume
cdev_del
// double free
cdev_device_del
And uif_close will race with ubi_cdev_ioctl as in the following stack.
cpu1 cpu2 cpu3
_______________________|________________________|______________________
ctrl_cdev_ioctl
ubi_attach_mtd_dev
uif_init
ubi_cdev_ioctl
ubi_create_volume
cdev_device_add
ubi_debugfs_init_dev
//error goto out_uif;
uif_close
kill_volumes
ubi_cdev_ioctl
ubi_remove_volume
cdev_device_del
// first free
ubi_free_volume
// double free
The cause of this problem is that commit 714fb87e8bc0 make device
"available" before it becomes accessible via sysfs. Therefore, we
roll back the modification. We will fix the race condition between
ubi device creation and udev by removing ubi_get_device in
vol_attribute_show and dev_attribute_show.This avoids accessing
uninitialized ubi_devices[ubi_num].
ubi_get_device is used to prevent devices from being deleted during
sysfs execution. However, now kernfs ensures that devices will not
be deleted before all reference counting are released.
The key process is shown in the following stack.
device_del
device_remove_attrs
device_remove_groups
sysfs_remove_groups
sysfs_remove_group
remove_files
kernfs_remove_by_name
kernfs_remove_by_name_ns
__kernfs_remove
kernfs_drain
CVSS Score
7.8
EPSS Score
0.001
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
ubifs: Fix to add refcount once page is set private
MM defined the rule [1] very clearly that once page was set with PG_private
flag, we should increment the refcount in that page, also main flows like
pageout(), migrate_page() will assume there is one additional page
reference count if page_has_private() returns true. Otherwise, we may
get a BUG in page migration:
page:0000000080d05b9d refcount:-1 mapcount:0 mapping:000000005f4d82a8
index:0xe2 pfn:0x14c12
aops:ubifs_file_address_operations [ubifs] ino:8f1 dentry name:"f30e"
flags: 0x1fffff80002405(locked|uptodate|owner_priv_1|private|node=0|
zone=1|lastcpupid=0x1fffff)
page dumped because: VM_BUG_ON_PAGE(page_count(page) != 0)
------------[ cut here ]------------
kernel BUG at include/linux/page_ref.h:184!
invalid opcode: 0000 [#1] SMP
CPU: 3 PID: 38 Comm: kcompactd0 Not tainted 5.15.0-rc5
RIP: 0010:migrate_page_move_mapping+0xac3/0xe70
Call Trace:
ubifs_migrate_page+0x22/0xc0 [ubifs]
move_to_new_page+0xb4/0x600
migrate_pages+0x1523/0x1cc0
compact_zone+0x8c5/0x14b0
kcompactd+0x2bc/0x560
kthread+0x18c/0x1e0
ret_from_fork+0x1f/0x30
Before the time, we should make clean a concept, what does refcount means
in page gotten from grab_cache_page_write_begin(). There are 2 situations:
Situation 1: refcount is 3, page is created by __page_cache_alloc.
TYPE_A - the write process is using this page
TYPE_B - page is assigned to one certain mapping by calling
__add_to_page_cache_locked()
TYPE_C - page is added into pagevec list corresponding current cpu by
calling lru_cache_add()
Situation 2: refcount is 2, page is gotten from the mapping's tree
TYPE_B - page has been assigned to one certain mapping
TYPE_A - the write process is using this page (by calling
page_cache_get_speculative())
Filesystem releases one refcount by calling put_page() in xxx_write_end(),
the released refcount corresponds to TYPE_A (write task is using it). If
there are any processes using a page, page migration process will skip the
page by judging whether expected_page_refs() equals to page refcount.
The BUG is caused by following process:
PA(cpu 0) kcompactd(cpu 1)
compact_zone
ubifs_write_begin
page_a = grab_cache_page_write_begin
add_to_page_cache_lru
lru_cache_add
pagevec_add // put page into cpu 0's pagevec
(refcnf = 3, for page creation process)
ubifs_write_end
SetPagePrivate(page_a) // doesn't increase page count !
unlock_page(page_a)
put_page(page_a) // refcnt = 2
[...]
PB(cpu 0)
filemap_read
filemap_get_pages
add_to_page_cache_lru
lru_cache_add
__pagevec_lru_add // traverse all pages in cpu 0's pagevec
__pagevec_lru_add_fn
SetPageLRU(page_a)
isolate_migratepages
isolate_migratepages_block
get_page_unless_zero(page_a)
// refcnt = 3
list_add(page_a, from_list)
migrate_pages(from_list)
__unmap_and_move
move_to_new_page
ubifs_migrate_page(page_a)
migrate_page_move_mapping
expected_page_refs get 3
(migration[1] + mapping[1] + private[1])
release_pages
put_page_testzero(page_a) // refcnt = 3
page_ref_freeze // refcnt = 0
page_ref_dec_and_test(0 - 1 = -1)
page_ref_unfreeze
VM_BUG_ON_PAGE(-1 != 0, page)
UBIFS doesn't increase the page refcount after setting private flag, which
leads to page migration task believes the page is not used by any other
processes, so the page is migrated. This causes concurrent accessing on
page refcount between put_page() called by other process(eg. read process
calls lru_cache_add) and page_ref_unfreeze() called by mi
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
ubifs: Fix read out-of-bounds in ubifs_wbuf_write_nolock()
Function ubifs_wbuf_write_nolock() may access buf out of bounds in
following process:
ubifs_wbuf_write_nolock():
aligned_len = ALIGN(len, 8); // Assume len = 4089, aligned_len = 4096
if (aligned_len <= wbuf->avail) ... // Not satisfy
if (wbuf->used) {
ubifs_leb_write() // Fill some data in avail wbuf
len -= wbuf->avail; // len is still not 8-bytes aligned
aligned_len -= wbuf->avail;
}
n = aligned_len >> c->max_write_shift;
if (n) {
n <<= c->max_write_shift;
err = ubifs_leb_write(c, wbuf->lnum, buf + written,
wbuf->offs, n);
// n > len, read out of bounds less than 8(n-len) bytes
}
, which can be catched by KASAN:
=========================================================
BUG: KASAN: slab-out-of-bounds in ecc_sw_hamming_calculate+0x1dc/0x7d0
Read of size 4 at addr ffff888105594ff8 by task kworker/u8:4/128
Workqueue: writeback wb_workfn (flush-ubifs_0_0)
Call Trace:
kasan_report.cold+0x81/0x165
nand_write_page_swecc+0xa9/0x160
ubifs_leb_write+0xf2/0x1b0 [ubifs]
ubifs_wbuf_write_nolock+0x421/0x12c0 [ubifs]
write_head+0xdc/0x1c0 [ubifs]
ubifs_jnl_write_inode+0x627/0x960 [ubifs]
wb_workfn+0x8af/0xb80
Function ubifs_wbuf_write_nolock() accepts that parameter 'len' is not 8
bytes aligned, the 'len' represents the true length of buf (which is
allocated in 'ubifs_jnl_xxx', eg. ubifs_jnl_write_inode), so
ubifs_wbuf_write_nolock() must handle the length read from 'buf' carefully
to write leb safely.
Fetch a reproducer in [Link].
CVSS Score
7.1
EPSS Score
0.0
Published
2025-02-26
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