Linux: >> Linux Kernel >> 6.1.9 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
can: isotp: split tx timer into transmission and timeout
The timer for the transmission of isotp PDUs formerly had two functions:
1. send two consecutive frames with a given time gap
2. monitor the timeouts for flow control frames and the echo frames
This led to larger txstate checks and potentially to a problem discovered
by syzbot which enabled the panic_on_warn feature while testing.
The former 'txtimer' function is split into 'txfrtimer' and 'txtimer'
to handle the two above functionalities with separate timer callbacks.
The two simplified timers now run in one-shot mode and make the state
transitions (especially with isotp_rcv_echo) better understandable.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-27
In the Linux kernel, the following vulnerability has been resolved:
cgroup/cpuset: Fix wrong check in update_parent_subparts_cpumask()
It was found that the check to see if a partition could use up all
the cpus from the parent cpuset in update_parent_subparts_cpumask()
was incorrect. As a result, it is possible to leave parent with no
effective cpu left even if there are tasks in the parent cpuset. This
can lead to system panic as reported in [1].
Fix this probem by updating the check to fail the enabling the partition
if parent's effective_cpus is a subset of the child's cpus_allowed.
Also record the error code when an error happens in update_prstate()
and add a test case where parent partition and child have the same cpu
list and parent has task. Enabling partition in the child will fail in
this case.
[1] https://www.spinics.net/lists/cgroups/msg36254.html
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-27
In the Linux kernel, the following vulnerability has been resolved:
vc_screen: move load of struct vc_data pointer in vcs_read() to avoid UAF
After a call to console_unlock() in vcs_read() the vc_data struct can be
freed by vc_deallocate(). Because of that, the struct vc_data pointer
load must be done at the top of while loop in vcs_read() to avoid a UAF
when vcs_size() is called.
Syzkaller reported a UAF in vcs_size().
BUG: KASAN: use-after-free in vcs_size (drivers/tty/vt/vc_screen.c:215)
Read of size 4 at addr ffff8881137479a8 by task 4a005ed81e27e65/1537
CPU: 0 PID: 1537 Comm: 4a005ed81e27e65 Not tainted 6.2.0-rc5 #1
Hardware name: Red Hat KVM, BIOS 1.15.0-2.module
Call Trace:
<TASK>
__asan_report_load4_noabort (mm/kasan/report_generic.c:350)
vcs_size (drivers/tty/vt/vc_screen.c:215)
vcs_read (drivers/tty/vt/vc_screen.c:415)
vfs_read (fs/read_write.c:468 fs/read_write.c:450)
...
</TASK>
Allocated by task 1191:
...
kmalloc_trace (mm/slab_common.c:1069)
vc_allocate (./include/linux/slab.h:580 ./include/linux/slab.h:720
drivers/tty/vt/vt.c:1128 drivers/tty/vt/vt.c:1108)
con_install (drivers/tty/vt/vt.c:3383)
tty_init_dev (drivers/tty/tty_io.c:1301 drivers/tty/tty_io.c:1413
drivers/tty/tty_io.c:1390)
tty_open (drivers/tty/tty_io.c:2080 drivers/tty/tty_io.c:2126)
chrdev_open (fs/char_dev.c:415)
do_dentry_open (fs/open.c:883)
vfs_open (fs/open.c:1014)
...
Freed by task 1548:
...
kfree (mm/slab_common.c:1021)
vc_port_destruct (drivers/tty/vt/vt.c:1094)
tty_port_destructor (drivers/tty/tty_port.c:296)
tty_port_put (drivers/tty/tty_port.c:312)
vt_disallocate_all (drivers/tty/vt/vt_ioctl.c:662 (discriminator 2))
vt_ioctl (drivers/tty/vt/vt_ioctl.c:903)
tty_ioctl (drivers/tty/tty_io.c:2776)
...
The buggy address belongs to the object at ffff888113747800
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 424 bytes inside of
1024-byte region [ffff888113747800, ffff888113747c00)
The buggy address belongs to the physical page:
page:00000000b3fe6c7c refcount:1 mapcount:0 mapping:0000000000000000
index:0x0 pfn:0x113740
head:00000000b3fe6c7c order:3 compound_mapcount:0 subpages_mapcount:0
compound_pincount:0
anon flags: 0x17ffffc0010200(slab|head|node=0|zone=2|lastcpupid=0x1fffff)
raw: 0017ffffc0010200 ffff888100042dc0 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888113747880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888113747900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff888113747980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888113747a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888113747a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Disabling lock debugging due to kernel taint
CVSS Score
7.8
EPSS Score
0.0
Published
2025-03-27
In the Linux kernel, the following vulnerability has been resolved:
scsi: iscsi_tcp: Fix UAF during login when accessing the shost ipaddress
If during iscsi_sw_tcp_session_create() iscsi_tcp_r2tpool_alloc() fails,
userspace could be accessing the host's ipaddress attr. If we then free the
session via iscsi_session_teardown() while userspace is still accessing the
session we will hit a use after free bug.
Set the tcp_sw_host->session after we have completed session creation and
can no longer fail.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-03-27
In the Linux kernel, the following vulnerability has been resolved:
scsi: iscsi_tcp: Fix UAF during logout when accessing the shost ipaddress
Bug report and analysis from Ding Hui.
During iSCSI session logout, if another task accesses the shost ipaddress
attr, we can get a KASAN UAF report like this:
[ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0
[ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088
[ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3
[ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020
[ 276.944470] Call Trace:
[ 276.944943] <TASK>
[ 276.945397] dump_stack_lvl+0x34/0x48
[ 276.945887] print_address_description.constprop.0+0x86/0x1e7
[ 276.946421] print_report+0x36/0x4f
[ 276.947358] kasan_report+0xad/0x130
[ 276.948234] kasan_check_range+0x35/0x1c0
[ 276.948674] _raw_spin_lock_bh+0x78/0xe0
[ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp]
[ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi]
[ 276.952185] dev_attr_show+0x3f/0x80
[ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0
[ 276.953401] seq_read_iter+0x402/0x1020
[ 276.954260] vfs_read+0x532/0x7b0
[ 276.955113] ksys_read+0xed/0x1c0
[ 276.955952] do_syscall_64+0x38/0x90
[ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 276.956769] RIP: 0033:0x7f5d3a679222
[ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24
[ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222
[ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003
[ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000
[ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000
[ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58
[ 276.960536] </TASK>
[ 276.961357] Allocated by task 2209:
[ 276.961756] kasan_save_stack+0x1e/0x40
[ 276.962170] kasan_set_track+0x21/0x30
[ 276.962557] __kasan_kmalloc+0x7e/0x90
[ 276.962923] __kmalloc+0x5b/0x140
[ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi]
[ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi]
[ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp]
[ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi]
[ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi]
[ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi]
[ 276.965546] netlink_unicast+0x4d5/0x7b0
[ 276.965905] netlink_sendmsg+0x78d/0xc30
[ 276.966236] sock_sendmsg+0xe5/0x120
[ 276.966576] ____sys_sendmsg+0x5fe/0x860
[ 276.966923] ___sys_sendmsg+0xe0/0x170
[ 276.967300] __sys_sendmsg+0xc8/0x170
[ 276.967666] do_syscall_64+0x38/0x90
[ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 276.968773] Freed by task 2209:
[ 276.969111] kasan_save_stack+0x1e/0x40
[ 276.969449] kasan_set_track+0x21/0x30
[ 276.969789] kasan_save_free_info+0x2a/0x50
[ 276.970146] __kasan_slab_free+0x106/0x190
[ 276.970470] __kmem_cache_free+0x133/0x270
[ 276.970816] device_release+0x98/0x210
[ 276.971145] kobject_cleanup+0x101/0x360
[ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi]
[ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp]
[ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi]
[ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi]
[ 276.972808] netlink_unicast+0x4d5/0x7b0
[ 276.973201] netlink_sendmsg+0x78d/0xc30
[ 276.973544] sock_sendmsg+0xe5/0x120
[ 276.973864] ____sys_sendmsg+0x5fe/0x860
[ 276.974248] ___sys_
---truncated---
CVSS Score
7.8
EPSS Score
0.001
Published
2025-03-27
In the Linux kernel, the following vulnerability has been resolved:
efi: fix potential NULL deref in efi_mem_reserve_persistent
When iterating on a linked list, a result of memremap is dereferenced
without checking it for NULL.
This patch adds a check that falls back on allocating a new page in
case memremap doesn't succeed.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
[ardb: return -ENOMEM instead of breaking out of the loop]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-27
In the Linux kernel, the following vulnerability has been resolved:
net: openvswitch: fix flow memory leak in ovs_flow_cmd_new
Syzkaller reports a memory leak of new_flow in ovs_flow_cmd_new() as it is
not freed when an allocation of a key fails.
BUG: memory leak
unreferenced object 0xffff888116668000 (size 632):
comm "syz-executor231", pid 1090, jiffies 4294844701 (age 18.871s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000defa3494>] kmem_cache_zalloc include/linux/slab.h:654 [inline]
[<00000000defa3494>] ovs_flow_alloc+0x19/0x180 net/openvswitch/flow_table.c:77
[<00000000c67d8873>] ovs_flow_cmd_new+0x1de/0xd40 net/openvswitch/datapath.c:957
[<0000000010a539a8>] genl_family_rcv_msg_doit+0x22d/0x330 net/netlink/genetlink.c:739
[<00000000dff3302d>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
[<00000000dff3302d>] genl_rcv_msg+0x328/0x590 net/netlink/genetlink.c:800
[<000000000286dd87>] netlink_rcv_skb+0x153/0x430 net/netlink/af_netlink.c:2515
[<0000000061fed410>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
[<000000009dc0f111>] netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
[<000000009dc0f111>] netlink_unicast+0x545/0x7f0 net/netlink/af_netlink.c:1339
[<000000004a5ee816>] netlink_sendmsg+0x8e7/0xde0 net/netlink/af_netlink.c:1934
[<00000000482b476f>] sock_sendmsg_nosec net/socket.c:651 [inline]
[<00000000482b476f>] sock_sendmsg+0x152/0x190 net/socket.c:671
[<00000000698574ba>] ____sys_sendmsg+0x70a/0x870 net/socket.c:2356
[<00000000d28d9e11>] ___sys_sendmsg+0xf3/0x170 net/socket.c:2410
[<0000000083ba9120>] __sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
[<00000000c00628f8>] do_syscall_64+0x30/0x40 arch/x86/entry/common.c:46
[<000000004abfdcf4>] entry_SYSCALL_64_after_hwframe+0x61/0xc6
To fix this the patch rearranges the goto labels to reflect the order of
object allocations and adds appropriate goto statements on the error
paths.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-27
In the Linux kernel, the following vulnerability has been resolved:
riscv: kprobe: Fixup kernel panic when probing an illegal position
The kernel would panic when probed for an illegal position. eg:
(CONFIG_RISCV_ISA_C=n)
echo 'p:hello kernel_clone+0x16 a0=%a0' >> kprobe_events
echo 1 > events/kprobes/hello/enable
cat trace
Kernel panic - not syncing: stack-protector: Kernel stack
is corrupted in: __do_sys_newfstatat+0xb8/0xb8
CPU: 0 PID: 111 Comm: sh Not tainted
6.2.0-rc1-00027-g2d398fe49a4d #490
Hardware name: riscv-virtio,qemu (DT)
Call Trace:
[<ffffffff80007268>] dump_backtrace+0x38/0x48
[<ffffffff80c5e83c>] show_stack+0x50/0x68
[<ffffffff80c6da28>] dump_stack_lvl+0x60/0x84
[<ffffffff80c6da6c>] dump_stack+0x20/0x30
[<ffffffff80c5ecf4>] panic+0x160/0x374
[<ffffffff80c6db94>] generic_handle_arch_irq+0x0/0xa8
[<ffffffff802deeb0>] sys_newstat+0x0/0x30
[<ffffffff800158c0>] sys_clone+0x20/0x30
[<ffffffff800039e8>] ret_from_syscall+0x0/0x4
---[ end Kernel panic - not syncing: stack-protector:
Kernel stack is corrupted in: __do_sys_newfstatat+0xb8/0xb8 ]---
That is because the kprobe's ebreak instruction broke the kernel's
original code. The user should guarantee the correction of the probe
position, but it couldn't make the kernel panic.
This patch adds arch_check_kprobe in arch_prepare_kprobe to prevent an
illegal position (Such as the middle of an instruction).
CVSS Score
5.5
EPSS Score
0.0
Published
2025-03-27
In the Linux kernel, the following vulnerability has been resolved:
Squashfs: fix handling and sanity checking of xattr_ids count
A Sysbot [1] corrupted filesystem exposes two flaws in the handling and
sanity checking of the xattr_ids count in the filesystem. Both of these
flaws cause computation overflow due to incorrect typing.
In the corrupted filesystem the xattr_ids value is 4294967071, which
stored in a signed variable becomes the negative number -225.
Flaw 1 (64-bit systems only):
The signed integer xattr_ids variable causes sign extension.
This causes variable overflow in the SQUASHFS_XATTR_*(A) macros. The
variable is first multiplied by sizeof(struct squashfs_xattr_id) where the
type of the sizeof operator is "unsigned long".
On a 64-bit system this is 64-bits in size, and causes the negative number
to be sign extended and widened to 64-bits and then become unsigned. This
produces the very large number 18446744073709548016 or 2^64 - 3600. This
number when rounded up by SQUASHFS_METADATA_SIZE - 1 (8191 bytes) and
divided by SQUASHFS_METADATA_SIZE overflows and produces a length of 0
(stored in len).
Flaw 2 (32-bit systems only):
On a 32-bit system the integer variable is not widened by the unsigned
long type of the sizeof operator (32-bits), and the signedness of the
variable has no effect due it always being treated as unsigned.
The above corrupted xattr_ids value of 4294967071, when multiplied
overflows and produces the number 4294963696 or 2^32 - 3400. This number
when rounded up by SQUASHFS_METADATA_SIZE - 1 (8191 bytes) and divided by
SQUASHFS_METADATA_SIZE overflows again and produces a length of 0.
The effect of the 0 length computation:
In conjunction with the corrupted xattr_ids field, the filesystem also has
a corrupted xattr_table_start value, where it matches the end of
filesystem value of 850.
This causes the following sanity check code to fail because the
incorrectly computed len of 0 matches the incorrect size of the table
reported by the superblock (0 bytes).
len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids);
indexes = SQUASHFS_XATTR_BLOCKS(*xattr_ids);
/*
* The computed size of the index table (len bytes) should exactly
* match the table start and end points
*/
start = table_start + sizeof(*id_table);
end = msblk->bytes_used;
if (len != (end - start))
return ERR_PTR(-EINVAL);
Changing the xattr_ids variable to be "usigned int" fixes the flaw on a
64-bit system. This relies on the fact the computation is widened by the
unsigned long type of the sizeof operator.
Casting the variable to u64 in the above macro fixes this flaw on a 32-bit
system.
It also means 64-bit systems do not implicitly rely on the type of the
sizeof operator to widen the computation.
[1] https://lore.kernel.org/lkml/000000000000cd44f005f1a0f17f@google.com/
CVSS Score
5.5
EPSS Score
0.001
Published
2025-03-27
In the Linux kernel, the following vulnerability has been resolved:
mm/MADV_COLLAPSE: catch !none !huge !bad pmd lookups
In commit 34488399fa08 ("mm/madvise: add file and shmem support to
MADV_COLLAPSE") we make the following change to find_pmd_or_thp_or_none():
- if (!pmd_present(pmde))
- return SCAN_PMD_NULL;
+ if (pmd_none(pmde))
+ return SCAN_PMD_NONE;
This was for-use by MADV_COLLAPSE file/shmem codepaths, where
MADV_COLLAPSE might identify a pte-mapped hugepage, only to have
khugepaged race-in, free the pte table, and clear the pmd. Such codepaths
include:
A) If we find a suitably-aligned compound page of order HPAGE_PMD_ORDER
already in the pagecache.
B) In retract_page_tables(), if we fail to grab mmap_lock for the target
mm/address.
In these cases, collapse_pte_mapped_thp() really does expect a none (not
just !present) pmd, and we want to suitably identify that case separate
from the case where no pmd is found, or it's a bad-pmd (of course, many
things could happen once we drop mmap_lock, and the pmd could plausibly
undergo multiple transitions due to intervening fault, split, etc).
Regardless, the code is prepared install a huge-pmd only when the existing
pmd entry is either a genuine pte-table-mapping-pmd, or the none-pmd.
However, the commit introduces a logical hole; namely, that we've allowed
!none- && !huge- && !bad-pmds to be classified as genuine
pte-table-mapping-pmds. One such example that could leak through are swap
entries. The pmd values aren't checked again before use in
pte_offset_map_lock(), which is expecting nothing less than a genuine
pte-table-mapping-pmd.
We want to put back the !pmd_present() check (below the pmd_none() check),
but need to be careful to deal with subtleties in pmd transitions and
treatments by various arch.
The issue is that __split_huge_pmd_locked() temporarily clears the present
bit (or otherwise marks the entry as invalid), but pmd_present() and
pmd_trans_huge() still need to return true while the pmd is in this
transitory state. For example, x86's pmd_present() also checks the
_PAGE_PSE , riscv's version also checks the _PAGE_LEAF bit, and arm64 also
checks a PMD_PRESENT_INVALID bit.
Covering all 4 cases for x86 (all checks done on the same pmd value):
1) pmd_present() && pmd_trans_huge()
All we actually know here is that the PSE bit is set. Either:
a) We aren't racing with __split_huge_page(), and PRESENT or PROTNONE
is set.
=> huge-pmd
b) We are currently racing with __split_huge_page(). The danger here
is that we proceed as-if we have a huge-pmd, but really we are
looking at a pte-mapping-pmd. So, what is the risk of this
danger?
The only relevant path is:
madvise_collapse() -> collapse_pte_mapped_thp()
Where we might just incorrectly report back "success", when really
the memory isn't pmd-backed. This is fine, since split could
happen immediately after (actually) successful madvise_collapse().
So, it should be safe to just assume huge-pmd here.
2) pmd_present() && !pmd_trans_huge()
Either:
a) PSE not set and either PRESENT or PROTNONE is.
=> pte-table-mapping pmd (or PROT_NONE)
b) devmap. This routine can be called immediately after
unlocking/locking mmap_lock -- or called with no locks held (see
khugepaged_scan_mm_slot()), so previous VMA checks have since been
invalidated.
3) !pmd_present() && pmd_trans_huge()
Not possible.
4) !pmd_present() && !pmd_trans_huge()
Neither PRESENT nor PROTNONE set
=> not present
I've checked all archs that implement pmd_trans_huge() (arm64, riscv,
powerpc, longarch, x86, mips, s390) and this logic roughly translates
(though devmap treatment is unique to x86 and powerpc, and (3) doesn't
necessarily hold in general -- but that doesn't matter since
!pmd_present() always takes failure path).
Also, add a comment above find_pmd_or_thp_or_none()
---truncated---
CVSS Score
4.7
EPSS Score
0.0
Published
2025-03-27