Linux: >> Linux Kernel >> 2.6.27.22 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
Drivers: hv: vmbus: Deactivate sysctl_record_panic_msg by default in isolated guests
hv_panic_page might contain guest-sensitive information, do not dump it
over to Hyper-V by default in isolated guests.
While at it, update some comments in hyperv_{panic,die}_event().
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Check for potential null return of kmalloc_array()
As the kmalloc_array() may return null, the 'event_waiters[i].wait' would lead to null-pointer dereference.
Therefore, it is better to check the return value of kmalloc_array() to avoid this confusion.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
samples/landlock: Fix path_list memory leak
Clang static analysis reports this error
sandboxer.c:134:8: warning: Potential leak of memory
pointed to by 'path_list'
ret = 0;
^
path_list is allocated in parse_path() but never freed.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
jffs2: fix use-after-free in jffs2_clear_xattr_subsystem
When we mount a jffs2 image, assume that the first few blocks of
the image are normal and contain at least one xattr-related inode,
but the next block is abnormal. As a result, an error is returned
in jffs2_scan_eraseblock(). jffs2_clear_xattr_subsystem() is then
called in jffs2_build_filesystem() and then again in
jffs2_do_fill_super().
Finally we can observe the following report:
==================================================================
BUG: KASAN: use-after-free in jffs2_clear_xattr_subsystem+0x95/0x6ac
Read of size 8 at addr ffff8881243384e0 by task mount/719
Call Trace:
dump_stack+0x115/0x16b
jffs2_clear_xattr_subsystem+0x95/0x6ac
jffs2_do_fill_super+0x84f/0xc30
jffs2_fill_super+0x2ea/0x4c0
mtd_get_sb+0x254/0x400
mtd_get_sb_by_nr+0x4f/0xd0
get_tree_mtd+0x498/0x840
jffs2_get_tree+0x25/0x30
vfs_get_tree+0x8d/0x2e0
path_mount+0x50f/0x1e50
do_mount+0x107/0x130
__se_sys_mount+0x1c5/0x2f0
__x64_sys_mount+0xc7/0x160
do_syscall_64+0x45/0x70
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Allocated by task 719:
kasan_save_stack+0x23/0x60
__kasan_kmalloc.constprop.0+0x10b/0x120
kasan_slab_alloc+0x12/0x20
kmem_cache_alloc+0x1c0/0x870
jffs2_alloc_xattr_ref+0x2f/0xa0
jffs2_scan_medium.cold+0x3713/0x4794
jffs2_do_mount_fs.cold+0xa7/0x2253
jffs2_do_fill_super+0x383/0xc30
jffs2_fill_super+0x2ea/0x4c0
[...]
Freed by task 719:
kmem_cache_free+0xcc/0x7b0
jffs2_free_xattr_ref+0x78/0x98
jffs2_clear_xattr_subsystem+0xa1/0x6ac
jffs2_do_mount_fs.cold+0x5e6/0x2253
jffs2_do_fill_super+0x383/0xc30
jffs2_fill_super+0x2ea/0x4c0
[...]
The buggy address belongs to the object at ffff8881243384b8
which belongs to the cache jffs2_xattr_ref of size 48
The buggy address is located 40 bytes inside of
48-byte region [ffff8881243384b8, ffff8881243384e8)
[...]
==================================================================
The triggering of the BUG is shown in the following stack:
-----------------------------------------------------------
jffs2_fill_super
jffs2_do_fill_super
jffs2_do_mount_fs
jffs2_build_filesystem
jffs2_scan_medium
jffs2_scan_eraseblock <--- ERROR
jffs2_clear_xattr_subsystem <--- free
jffs2_clear_xattr_subsystem <--- free again
-----------------------------------------------------------
An error is returned in jffs2_do_mount_fs(). If the error is returned
by jffs2_sum_init(), the jffs2_clear_xattr_subsystem() does not need to
be executed. If the error is returned by jffs2_build_filesystem(), the
jffs2_clear_xattr_subsystem() also does not need to be executed again.
So move jffs2_clear_xattr_subsystem() from 'out_inohash' to 'out_root'
to fix this UAF problem.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-02-26
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:
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