Linux: >> Linux Kernel >> 2.6.27.6 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ASoC: topology: Fix references to freed memory
Most users after parsing a topology file, release memory used by it, so
having pointer references directly into topology file contents is wrong.
Use devm_kmemdup(), to allocate memory as needed.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
KVM: PPC: Book3S HV: Prevent UAF in kvm_spapr_tce_attach_iommu_group()
Al reported a possible use-after-free (UAF) in kvm_spapr_tce_attach_iommu_group().
It looks up `stt` from tablefd, but then continues to use it after doing
fdput() on the returned fd. After the fdput() the tablefd is free to be
closed by another thread. The close calls kvm_spapr_tce_release() and
then release_spapr_tce_table() (via call_rcu()) which frees `stt`.
Although there are calls to rcu_read_lock() in
kvm_spapr_tce_attach_iommu_group() they are not sufficient to prevent
the UAF, because `stt` is used outside the locked regions.
With an artifcial delay after the fdput() and a userspace program which
triggers the race, KASAN detects the UAF:
BUG: KASAN: slab-use-after-free in kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm]
Read of size 4 at addr c000200027552c30 by task kvm-vfio/2505
CPU: 54 PID: 2505 Comm: kvm-vfio Not tainted 6.10.0-rc3-next-20240612-dirty #1
Hardware name: 8335-GTH POWER9 0x4e1202 opal:skiboot-v6.5.3-35-g1851b2a06 PowerNV
Call Trace:
dump_stack_lvl+0xb4/0x108 (unreliable)
print_report+0x2b4/0x6ec
kasan_report+0x118/0x2b0
__asan_load4+0xb8/0xd0
kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm]
kvm_vfio_set_attr+0x524/0xac0 [kvm]
kvm_device_ioctl+0x144/0x240 [kvm]
sys_ioctl+0x62c/0x1810
system_call_exception+0x190/0x440
system_call_vectored_common+0x15c/0x2ec
...
Freed by task 0:
...
kfree+0xec/0x3e0
release_spapr_tce_table+0xd4/0x11c [kvm]
rcu_core+0x568/0x16a0
handle_softirqs+0x23c/0x920
do_softirq_own_stack+0x6c/0x90
do_softirq_own_stack+0x58/0x90
__irq_exit_rcu+0x218/0x2d0
irq_exit+0x30/0x80
arch_local_irq_restore+0x128/0x230
arch_local_irq_enable+0x1c/0x30
cpuidle_enter_state+0x134/0x5cc
cpuidle_enter+0x6c/0xb0
call_cpuidle+0x7c/0x100
do_idle+0x394/0x410
cpu_startup_entry+0x60/0x70
start_secondary+0x3fc/0x410
start_secondary_prolog+0x10/0x14
Fix it by delaying the fdput() until `stt` is no longer in use, which
is effectively the entire function. To keep the patch minimal add a call
to fdput() at each of the existing return paths. Future work can convert
the function to goto or __cleanup style cleanup.
With the fix in place the test case no longer triggers the UAF.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: wext: add extra SIOCSIWSCAN data check
In 'cfg80211_wext_siwscan()', add extra check whether number of
channels passed via 'ioctl(sock, SIOCSIWSCAN, ...)' doesn't exceed
IW_MAX_FREQUENCIES and reject invalid request with -EINVAL otherwise.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
hfsplus: fix uninit-value in copy_name
[syzbot reported]
BUG: KMSAN: uninit-value in sized_strscpy+0xc4/0x160
sized_strscpy+0xc4/0x160
copy_name+0x2af/0x320 fs/hfsplus/xattr.c:411
hfsplus_listxattr+0x11e9/0x1a50 fs/hfsplus/xattr.c:750
vfs_listxattr fs/xattr.c:493 [inline]
listxattr+0x1f3/0x6b0 fs/xattr.c:840
path_listxattr fs/xattr.c:864 [inline]
__do_sys_listxattr fs/xattr.c:876 [inline]
__se_sys_listxattr fs/xattr.c:873 [inline]
__x64_sys_listxattr+0x16b/0x2f0 fs/xattr.c:873
x64_sys_call+0x2ba0/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:195
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Uninit was created at:
slab_post_alloc_hook mm/slub.c:3877 [inline]
slab_alloc_node mm/slub.c:3918 [inline]
kmalloc_trace+0x57b/0xbe0 mm/slub.c:4065
kmalloc include/linux/slab.h:628 [inline]
hfsplus_listxattr+0x4cc/0x1a50 fs/hfsplus/xattr.c:699
vfs_listxattr fs/xattr.c:493 [inline]
listxattr+0x1f3/0x6b0 fs/xattr.c:840
path_listxattr fs/xattr.c:864 [inline]
__do_sys_listxattr fs/xattr.c:876 [inline]
__se_sys_listxattr fs/xattr.c:873 [inline]
__x64_sys_listxattr+0x16b/0x2f0 fs/xattr.c:873
x64_sys_call+0x2ba0/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:195
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
[Fix]
When allocating memory to strbuf, initialize memory to 0.
CVSS Score
7.1
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
ppp: reject claimed-as-LCP but actually malformed packets
Since 'ppp_async_encode()' assumes valid LCP packets (with code
from 1 to 7 inclusive), add 'ppp_check_packet()' to ensure that
LCP packet has an actual body beyond PPP_LCP header bytes, and
reject claimed-as-LCP but actually malformed data otherwise.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
filelock: Fix fcntl/close race recovery compat path
When I wrote commit 3cad1bc01041 ("filelock: Remove locks reliably when
fcntl/close race is detected"), I missed that there are two copies of the
code I was patching: The normal version, and the version for 64-bit offsets
on 32-bit kernels.
Thanks to Greg KH for stumbling over this while doing the stable
backport...
Apply exactly the same fix to the compat path for 32-bit kernels.
CVSS Score
4.7
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: add bounds checking to ocfs2_check_dir_entry()
This adds sanity checks for ocfs2_dir_entry to make sure all members of
ocfs2_dir_entry don't stray beyond valid memory region.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: strict bound check before memcmp in ocfs2_xattr_find_entry()
xattr in ocfs2 maybe 'non-indexed', which saved with additional space
requested. It's better to check if the memory is out of bound before
memcmp, although this possibility mainly comes from crafted poisonous
images.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
jfs: don't walk off the end of ealist
Add a check before visiting the members of ea to
make sure each ea stays within the ealist.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-07-29
In the Linux kernel, the following vulnerability has been resolved:
xfs: don't walk off the end of a directory data block
This adds sanity checks for xfs_dir2_data_unused and xfs_dir2_data_entry
to make sure don't stray beyond valid memory region. Before patching, the
loop simply checks that the start offset of the dup and dep is within the
range. So in a crafted image, if last entry is xfs_dir2_data_unused, we
can change dup->length to dup->length-1 and leave 1 byte of space. In the
next traversal, this space will be considered as dup or dep. We may
encounter an out of bound read when accessing the fixed members.
In the patch, we make sure that the remaining bytes large enough to hold
an unused entry before accessing xfs_dir2_data_unused and
xfs_dir2_data_unused is XFS_DIR2_DATA_ALIGN byte aligned. We also make
sure that the remaining bytes large enough to hold a dirent with a
single-byte name before accessing xfs_dir2_data_entry.
CVSS Score
7.1
EPSS Score
0.0
Published
2024-07-29