Linux: >> Linux Kernel >> 4.11.2 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
pptp: ensure minimal skb length in pptp_xmit()
Commit aabc6596ffb3 ("net: ppp: Add bound checking for skb data
on ppp_sync_txmung") fixed ppp_sync_txmunge()
We need a similar fix in pptp_xmit(), otherwise we might
read uninit data as reported by syzbot.
BUG: KMSAN: uninit-value in pptp_xmit+0xc34/0x2720 drivers/net/ppp/pptp.c:193
pptp_xmit+0xc34/0x2720 drivers/net/ppp/pptp.c:193
ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2290 [inline]
ppp_input+0x1d6/0xe60 drivers/net/ppp/ppp_generic.c:2314
pppoe_rcv_core+0x1e8/0x760 drivers/net/ppp/pppoe.c:379
sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148
__release_sock+0x1d3/0x330 net/core/sock.c:3213
release_sock+0x6b/0x270 net/core/sock.c:3767
pppoe_sendmsg+0x15d/0xcb0 drivers/net/ppp/pppoe.c:904
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x330/0x3d0 net/socket.c:727
____sys_sendmsg+0x893/0xd80 net/socket.c:2566
___sys_sendmsg+0x271/0x3b0 net/socket.c:2620
__sys_sendmmsg+0x2d9/0x7c0 net/socket.c:2709
CVSS Score
7.8
EPSS Score
0.0
Published
2025-08-19
In the Linux kernel, the following vulnerability has been resolved:
powerpc/eeh: Make EEH driver device hotplug safe
Multiple race conditions existed between the PCIe hotplug driver and the
EEH driver, leading to a variety of kernel oopses of the same general
nature:
<pcie device unplug>
<eeh driver trigger>
<hotplug removal trigger>
<pcie tree reconfiguration>
<eeh recovery next step>
<oops in EEH driver bus iteration loop>
A second class of oops is also seen when the underlying bus disappears
during device recovery.
Refactor the EEH module to be PCI rescan and remove safe. Also clean
up a few minor formatting / readability issues.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-08-19
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid panic in f2fs_evict_inode
As syzbot [1] reported as below:
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffe17473450
R13: 00007f28b1c10854 R14: 000000000000dae5 R15: 00007ffe17474520
</TASK>
---[ end trace 0000000000000000 ]---
==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0xa6/0x130 lib/list_debug.c:62
Read of size 8 at addr ffff88812d962278 by task syz-executor/564
CPU: 1 PID: 564 Comm: syz-executor Tainted: G W 6.1.129-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__dump_stack+0x21/0x24 lib/dump_stack.c:88
dump_stack_lvl+0xee/0x158 lib/dump_stack.c:106
print_address_description+0x71/0x210 mm/kasan/report.c:316
print_report+0x4a/0x60 mm/kasan/report.c:427
kasan_report+0x122/0x150 mm/kasan/report.c:531
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:351
__list_del_entry_valid+0xa6/0x130 lib/list_debug.c:62
__list_del_entry include/linux/list.h:134 [inline]
list_del_init include/linux/list.h:206 [inline]
f2fs_inode_synced+0xf7/0x2e0 fs/f2fs/super.c:1531
f2fs_update_inode+0x74/0x1c40 fs/f2fs/inode.c:585
f2fs_update_inode_page+0x137/0x170 fs/f2fs/inode.c:703
f2fs_write_inode+0x4ec/0x770 fs/f2fs/inode.c:731
write_inode fs/fs-writeback.c:1460 [inline]
__writeback_single_inode+0x4a0/0xab0 fs/fs-writeback.c:1677
writeback_single_inode+0x221/0x8b0 fs/fs-writeback.c:1733
sync_inode_metadata+0xb6/0x110 fs/fs-writeback.c:2789
f2fs_sync_inode_meta+0x16d/0x2a0 fs/f2fs/checkpoint.c:1159
block_operations fs/f2fs/checkpoint.c:1269 [inline]
f2fs_write_checkpoint+0xca3/0x2100 fs/f2fs/checkpoint.c:1658
kill_f2fs_super+0x231/0x390 fs/f2fs/super.c:4668
deactivate_locked_super+0x98/0x100 fs/super.c:332
deactivate_super+0xaf/0xe0 fs/super.c:363
cleanup_mnt+0x45f/0x4e0 fs/namespace.c:1186
__cleanup_mnt+0x19/0x20 fs/namespace.c:1193
task_work_run+0x1c6/0x230 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0x9fb/0x2410 kernel/exit.c:871
do_group_exit+0x210/0x2d0 kernel/exit.c:1021
__do_sys_exit_group kernel/exit.c:1032 [inline]
__se_sys_exit_group kernel/exit.c:1030 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1030
x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f28b1b8e169
Code: Unable to access opcode bytes at 0x7f28b1b8e13f.
RSP: 002b:00007ffe174710a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f28b1c10879 RCX: 00007f28b1b8e169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000002 R08: 00007ffe1746ee47 R09: 00007ffe17472360
R10: 0000000000000009 R11: 0000000000000246 R12: 00007ffe17472360
R13: 00007f28b1c10854 R14: 000000000000dae5 R15: 00007ffe17474520
</TASK>
Allocated by task 569:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505
__kasan_slab_alloc+0x72/0x80 mm/kasan/common.c:328
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook+0x4f/0x2c0 mm/slab.h:737
slab_alloc_node mm/slub.c:3398 [inline]
slab_alloc mm/slub.c:3406 [inline]
__kmem_cache_alloc_lru mm/slub.c:3413 [inline]
kmem_cache_alloc_lru+0x104/0x220 mm/slub.c:3429
alloc_inode_sb include/linux/fs.h:3245 [inline]
f2fs_alloc_inode+0x2d/0x340 fs/f2fs/super.c:1419
alloc_inode fs/inode.c:261 [inline]
iget_locked+0x186/0x880 fs/inode.c:1373
f2fs_iget+0x55/0x4c60 fs/f2fs/inode.c:483
f2fs_lookup+0x366/0xab0 fs/f2fs/namei.c:487
__lookup_slow+0x2a3/0x3d0 fs/namei.c:1690
lookup_slow+0x57/0x70 fs/namei.c:1707
walk_component+0x2e6/0x410 fs/namei
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-08-19
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid UAF in f2fs_sync_inode_meta()
syzbot reported an UAF issue as below: [1] [2]
[1] https://syzkaller.appspot.com/text?tag=CrashReport&x=16594c60580000
==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0xa6/0x130 lib/list_debug.c:62
Read of size 8 at addr ffff888100567dc8 by task kworker/u4:0/8
CPU: 1 PID: 8 Comm: kworker/u4:0 Tainted: G W 6.1.129-syzkaller-00017-g642656a36791 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:316 [inline]
print_report+0x158/0x4e0 mm/kasan/report.c:427
kasan_report+0x13c/0x170 mm/kasan/report.c:531
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:351
__list_del_entry_valid+0xa6/0x130 lib/list_debug.c:62
__list_del_entry include/linux/list.h:134 [inline]
list_del_init include/linux/list.h:206 [inline]
f2fs_inode_synced+0x100/0x2e0 fs/f2fs/super.c:1553
f2fs_update_inode+0x72/0x1c40 fs/f2fs/inode.c:588
f2fs_update_inode_page+0x135/0x170 fs/f2fs/inode.c:706
f2fs_write_inode+0x416/0x790 fs/f2fs/inode.c:734
write_inode fs/fs-writeback.c:1460 [inline]
__writeback_single_inode+0x4cf/0xb80 fs/fs-writeback.c:1677
writeback_sb_inodes+0xb32/0x1910 fs/fs-writeback.c:1903
__writeback_inodes_wb+0x118/0x3f0 fs/fs-writeback.c:1974
wb_writeback+0x3da/0xa00 fs/fs-writeback.c:2081
wb_check_background_flush fs/fs-writeback.c:2151 [inline]
wb_do_writeback fs/fs-writeback.c:2239 [inline]
wb_workfn+0xbba/0x1030 fs/fs-writeback.c:2266
process_one_work+0x73d/0xcb0 kernel/workqueue.c:2299
worker_thread+0xa60/0x1260 kernel/workqueue.c:2446
kthread+0x26d/0x300 kernel/kthread.c:386
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Allocated by task 298:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:333
kasan_slab_alloc include/linux/kasan.h:202 [inline]
slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:768
slab_alloc_node mm/slub.c:3421 [inline]
slab_alloc mm/slub.c:3431 [inline]
__kmem_cache_alloc_lru mm/slub.c:3438 [inline]
kmem_cache_alloc_lru+0x102/0x270 mm/slub.c:3454
alloc_inode_sb include/linux/fs.h:3255 [inline]
f2fs_alloc_inode+0x2d/0x350 fs/f2fs/super.c:1437
alloc_inode fs/inode.c:261 [inline]
iget_locked+0x18c/0x7e0 fs/inode.c:1373
f2fs_iget+0x55/0x4ca0 fs/f2fs/inode.c:486
f2fs_lookup+0x3c1/0xb50 fs/f2fs/namei.c:484
__lookup_slow+0x2b9/0x3e0 fs/namei.c:1689
lookup_slow+0x5a/0x80 fs/namei.c:1706
walk_component+0x2e7/0x410 fs/namei.c:1997
lookup_last fs/namei.c:2454 [inline]
path_lookupat+0x16d/0x450 fs/namei.c:2478
filename_lookup+0x251/0x600 fs/namei.c:2507
vfs_statx+0x107/0x4b0 fs/stat.c:229
vfs_fstatat fs/stat.c:267 [inline]
vfs_lstat include/linux/fs.h:3434 [inline]
__do_sys_newlstat fs/stat.c:423 [inline]
__se_sys_newlstat+0xda/0x7c0 fs/stat.c:417
__x64_sys_newlstat+0x5b/0x70 fs/stat.c:417
x64_sys_call+0x52/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:7
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Freed by task 0:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516
____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241
__kasan_slab_free+0x11/0x20 mm/kasan/common.c:249
kasan_slab_free include/linux/kasan.h:178 [inline]
slab_free_hook mm/slub.c:1745 [inline]
slab_free_freelist_hook mm/slub.c:1771 [inline]
slab_free mm/slub.c:3686 [inline]
kmem_cache_free+0x
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-08-19
In the Linux kernel, the following vulnerability has been resolved:
perf/core: Exit early on perf_mmap() fail
When perf_mmap() fails to allocate a buffer, it still invokes the
event_mapped() callback of the related event. On X86 this might increase
the perf_rdpmc_allowed reference counter. But nothing undoes this as
perf_mmap_close() is never called in this case, which causes another
reference count leak.
Return early on failure to prevent that.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-08-19
In the Linux kernel, the following vulnerability has been resolved:
perf/core: Prevent VMA split of buffer mappings
The perf mmap code is careful about mmap()'ing the user page with the
ringbuffer and additionally the auxiliary buffer, when the event supports
it. Once the first mapping is established, subsequent mapping have to use
the same offset and the same size in both cases. The reference counting for
the ringbuffer and the auxiliary buffer depends on this being correct.
Though perf does not prevent that a related mapping is split via mmap(2),
munmap(2) or mremap(2). A split of a VMA results in perf_mmap_open() calls,
which take reference counts, but then the subsequent perf_mmap_close()
calls are not longer fulfilling the offset and size checks. This leads to
reference count leaks.
As perf already has the requirement for subsequent mappings to match the
initial mapping, the obvious consequence is that VMA splits, caused by
resizing of a mapping or partial unmapping, have to be prevented.
Implement the vm_operations_struct::may_split() callback and return
unconditionally -EINVAL.
That ensures that the mapping offsets and sizes cannot be changed after the
fact. Remapping to a different fixed address with the same size is still
possible as it takes the references for the new mapping and drops those of
the old mapping.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-08-19
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget : fix use-after-free in composite_dev_cleanup()
1. In func configfs_composite_bind() -> composite_os_desc_req_prepare():
if kmalloc fails, the pointer cdev->os_desc_req will be freed but not
set to NULL. Then it will return a failure to the upper-level function.
2. in func configfs_composite_bind() -> composite_dev_cleanup():
it will checks whether cdev->os_desc_req is NULL. If it is not NULL, it
will attempt to use it.This will lead to a use-after-free issue.
BUG: KASAN: use-after-free in composite_dev_cleanup+0xf4/0x2c0
Read of size 8 at addr 0000004827837a00 by task init/1
CPU: 10 PID: 1 Comm: init Tainted: G O 5.10.97-oh #1
kasan_report+0x188/0x1cc
__asan_load8+0xb4/0xbc
composite_dev_cleanup+0xf4/0x2c0
configfs_composite_bind+0x210/0x7ac
udc_bind_to_driver+0xb4/0x1ec
usb_gadget_probe_driver+0xec/0x21c
gadget_dev_desc_UDC_store+0x264/0x27c
CVSS Score
7.8
EPSS Score
0.0
Published
2025-08-19
In the Linux kernel, the following vulnerability has been resolved:
HID: core: Harden s32ton() against conversion to 0 bits
Testing by the syzbot fuzzer showed that the HID core gets a
shift-out-of-bounds exception when it tries to convert a 32-bit
quantity to a 0-bit quantity. Ideally this should never occur, but
there are buggy devices and some might have a report field with size
set to zero; we shouldn't reject the report or the device just because
of that.
Instead, harden the s32ton() routine so that it returns a reasonable
result instead of crashing when it is called with the number of bits
set to 0 -- the same as what snto32() does.
CVSS Score
7.1
EPSS Score
0.0
Published
2025-08-19
In the Linux kernel, the following vulnerability has been resolved:
net/sched: Restrict conditions for adding duplicating netems to qdisc tree
netem_enqueue's duplication prevention logic breaks when a netem
resides in a qdisc tree with other netems - this can lead to a
soft lockup and OOM loop in netem_dequeue, as seen in [1].
Ensure that a duplicating netem cannot exist in a tree with other
netems.
Previous approaches suggested in discussions in chronological order:
1) Track duplication status or ttl in the sk_buff struct. Considered
too specific a use case to extend such a struct, though this would
be a resilient fix and address other previous and potential future
DOS bugs like the one described in loopy fun [2].
2) Restrict netem_enqueue recursion depth like in act_mirred with a
per cpu variable. However, netem_dequeue can call enqueue on its
child, and the depth restriction could be bypassed if the child is a
netem.
3) Use the same approach as in 2, but add metadata in netem_skb_cb
to handle the netem_dequeue case and track a packet's involvement
in duplication. This is an overly complex approach, and Jamal
notes that the skb cb can be overwritten to circumvent this
safeguard.
4) Prevent the addition of a netem to a qdisc tree if its ancestral
path contains a netem. However, filters and actions can cause a
packet to change paths when re-enqueued to the root from netem
duplication, leading us to the current solution: prevent a
duplicating netem from inhabiting the same tree as other netems.
[1] https://lore.kernel.org/netdev/8DuRWwfqjoRDLDmBMlIfbrsZg9Gx50DHJc1ilxsEBNe2D6NMoigR_eIRIG0LOjMc3r10nUUZtArXx4oZBIdUfZQrwjcQhdinnMis_0G7VEk=@willsroot.io/
[2] https://lwn.net/Articles/719297/
CVSS Score
5.5
EPSS Score
0.0
Published
2025-08-19
In the Linux kernel, the following vulnerability has been resolved:
net: appletalk: Fix device refcount leak in atrtr_create()
When updating an existing route entry in atrtr_create(), the old device
reference was not being released before assigning the new device,
leading to a device refcount leak. Fix this by calling dev_put() to
release the old device reference before holding the new one.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-08-16