Linux: >> Linux Kernel >> 2.6.22.7 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix qgroup reserve overflow the qgroup limit
We use extent_changeset->bytes_changed in qgroup_reserve_data() to record
how many bytes we set for EXTENT_QGROUP_RESERVED state. Currently the
bytes_changed is set as "unsigned int", and it will overflow if we try to
fallocate a range larger than 4GiB. The result is we reserve less bytes
and eventually break the qgroup limit.
Unlike regular buffered/direct write, which we use one changeset for
each ordered extent, which can never be larger than 256M. For
fallocate, we use one changeset for the whole range, thus it no longer
respects the 256M per extent limit, and caused the problem.
The following example test script reproduces the problem:
$ cat qgroup-overflow.sh
#!/bin/bash
DEV=/dev/sdj
MNT=/mnt/sdj
mkfs.btrfs -f $DEV
mount $DEV $MNT
# Set qgroup limit to 2GiB.
btrfs quota enable $MNT
btrfs qgroup limit 2G $MNT
# Try to fallocate a 3GiB file. This should fail.
echo
echo "Try to fallocate a 3GiB file..."
fallocate -l 3G $MNT/3G.file
# Try to fallocate a 5GiB file.
echo
echo "Try to fallocate a 5GiB file..."
fallocate -l 5G $MNT/5G.file
# See we break the qgroup limit.
echo
sync
btrfs qgroup show -r $MNT
umount $MNT
When running the test:
$ ./qgroup-overflow.sh
(...)
Try to fallocate a 3GiB file...
fallocate: fallocate failed: Disk quota exceeded
Try to fallocate a 5GiB file...
qgroupid rfer excl max_rfer
-------- ---- ---- --------
0/5 5.00GiB 5.00GiB 2.00GiB
Since we have no control of how bytes_changed is used, it's better to
set it to u64.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
powerpc: Fix virt_addr_valid() for 64-bit Book3E & 32-bit
mpe: On 64-bit Book3E vmalloc space starts at 0x8000000000000000.
Because of the way __pa() works we have:
__pa(0x8000000000000000) == 0, and therefore
virt_to_pfn(0x8000000000000000) == 0, and therefore
virt_addr_valid(0x8000000000000000) == true
Which is wrong, virt_addr_valid() should be false for vmalloc space.
In fact all vmalloc addresses that alias with a valid PFN will return
true from virt_addr_valid(). That can cause bugs with hardened usercopy
as described below by Kefeng Wang:
When running ethtool eth0 on 64-bit Book3E, a BUG occurred:
usercopy: Kernel memory exposure attempt detected from SLUB object not in SLUB page?! (offset 0, size 1048)!
kernel BUG at mm/usercopy.c:99
...
usercopy_abort+0x64/0xa0 (unreliable)
__check_heap_object+0x168/0x190
__check_object_size+0x1a0/0x200
dev_ethtool+0x2494/0x2b20
dev_ioctl+0x5d0/0x770
sock_do_ioctl+0xf0/0x1d0
sock_ioctl+0x3ec/0x5a0
__se_sys_ioctl+0xf0/0x160
system_call_exception+0xfc/0x1f0
system_call_common+0xf8/0x200
The code shows below,
data = vzalloc(array_size(gstrings.len, ETH_GSTRING_LEN));
copy_to_user(useraddr, data, gstrings.len * ETH_GSTRING_LEN))
The data is alloced by vmalloc(), virt_addr_valid(ptr) will return true
on 64-bit Book3E, which leads to the panic.
As commit 4dd7554a6456 ("powerpc/64: Add VIRTUAL_BUG_ON checks for __va
and __pa addresses") does, make sure the virt addr above PAGE_OFFSET in
the virt_addr_valid() for 64-bit, also add upper limit check to make
sure the virt is below high_memory.
Meanwhile, for 32-bit PAGE_OFFSET is the virtual address of the start
of lowmem, high_memory is the upper low virtual address, the check is
suitable for 32-bit, this will fix the issue mentioned in commit
602946ec2f90 ("powerpc: Set max_mapnr correctly") too.
On 32-bit there is a similar problem with high memory, that was fixed in
commit 602946ec2f90 ("powerpc: Set max_mapnr correctly"), but that
commit breaks highmem and needs to be reverted.
We can't easily fix __pa(), we have code that relies on its current
behaviour. So for now add extra checks to virt_addr_valid().
For 64-bit Book3S the extra checks are not necessary, the combination of
virt_to_pfn() and pfn_valid() should yield the correct result, but they
are harmless.
[mpe: Add additional change log detail]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
scsi: target: tcmu: Fix possible page UAF
tcmu_try_get_data_page() looks up pages under cmdr_lock, but it does not
take refcount properly and just returns page pointer. When
tcmu_try_get_data_page() returns, the returned page may have been freed by
tcmu_blocks_release().
We need to get_page() under cmdr_lock to avoid concurrent
tcmu_blocks_release().
CVSS Score
7.8
EPSS Score
0.001
Published
2025-02-26
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