Linux: >> Linux Kernel >> 5.6.19 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: avoid skb access on nf_stolen
When verdict is NF_STOLEN, the skb might have been freed.
When tracing is enabled, this can result in a use-after-free:
1. access to skb->nf_trace
2. access to skb->mark
3. computation of trace id
4. dump of packet payload
To avoid 1, keep a cached copy of skb->nf_trace in the
trace state struct.
Refresh this copy whenever verdict is != STOLEN.
Avoid 2 by skipping skb->mark access if verdict is STOLEN.
3 is avoided by precomputing the trace id.
Only dump the packet when verdict is not "STOLEN".
CVSS Score
7.8
EPSS Score
0.001
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
powerpc/xive/spapr: correct bitmap allocation size
kasan detects access beyond the end of the xibm->bitmap allocation:
BUG: KASAN: slab-out-of-bounds in _find_first_zero_bit+0x40/0x140
Read of size 8 at addr c00000001d1d0118 by task swapper/0/1
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc2-00001-g90df023b36dd #28
Call Trace:
[c00000001d98f770] [c0000000012baab8] dump_stack_lvl+0xac/0x108 (unreliable)
[c00000001d98f7b0] [c00000000068faac] print_report+0x37c/0x710
[c00000001d98f880] [c0000000006902c0] kasan_report+0x110/0x354
[c00000001d98f950] [c000000000692324] __asan_load8+0xa4/0xe0
[c00000001d98f970] [c0000000011c6ed0] _find_first_zero_bit+0x40/0x140
[c00000001d98f9b0] [c0000000000dbfbc] xive_spapr_get_ipi+0xcc/0x260
[c00000001d98fa70] [c0000000000d6d28] xive_setup_cpu_ipi+0x1e8/0x450
[c00000001d98fb30] [c000000004032a20] pSeries_smp_probe+0x5c/0x118
[c00000001d98fb60] [c000000004018b44] smp_prepare_cpus+0x944/0x9ac
[c00000001d98fc90] [c000000004009f9c] kernel_init_freeable+0x2d4/0x640
[c00000001d98fd90] [c0000000000131e8] kernel_init+0x28/0x1d0
[c00000001d98fe10] [c00000000000cd54] ret_from_kernel_thread+0x5c/0x64
Allocated by task 0:
kasan_save_stack+0x34/0x70
__kasan_kmalloc+0xb4/0xf0
__kmalloc+0x268/0x540
xive_spapr_init+0x4d0/0x77c
pseries_init_irq+0x40/0x27c
init_IRQ+0x44/0x84
start_kernel+0x2a4/0x538
start_here_common+0x1c/0x20
The buggy address belongs to the object at c00000001d1d0118
which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes inside of
8-byte region [c00000001d1d0118, c00000001d1d0120)
The buggy address belongs to the physical page:
page:c00c000000074740 refcount:1 mapcount:0 mapping:0000000000000000 index:0xc00000001d1d0558 pfn:0x1d1d
flags: 0x7ffff000000200(slab|node=0|zone=0|lastcpupid=0x7ffff)
raw: 007ffff000000200 c00000001d0003c8 c00000001d0003c8 c00000001d010480
raw: c00000001d1d0558 0000000001e1000a 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
c00000001d1d0000: fc 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
c00000001d1d0080: fc fc 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
>c00000001d1d0100: fc fc fc 02 fc fc fc fc fc fc fc fc fc fc fc fc
^
c00000001d1d0180: fc fc fc fc 04 fc fc fc fc fc fc fc fc fc fc fc
c00000001d1d0200: fc fc fc fc fc 04 fc fc fc fc fc fc fc fc fc fc
This happens because the allocation uses the wrong unit (bits) when it
should pass (BITS_TO_LONGS(count) * sizeof(long)) or equivalent. With small
numbers of bits, the allocated object can be smaller than sizeof(long),
which results in invalid accesses.
Use bitmap_zalloc() to allocate and initialize the irq bitmap, paired with
bitmap_free() for consistency.
CVSS Score
7.1
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
sfc: fix kernel panic when creating VF
When creating VFs a kernel panic can happen when calling to
efx_ef10_try_update_nic_stats_vf.
When releasing a DMA coherent buffer, sometimes, I don't know in what
specific circumstances, it has to unmap memory with vunmap. It is
disallowed to do that in IRQ context or with BH disabled. Otherwise, we
hit this line in vunmap, causing the crash:
BUG_ON(in_interrupt());
This patch reenables BH to release the buffer.
Log messages when the bug is hit:
kernel BUG at mm/vmalloc.c:2727!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 6 PID: 1462 Comm: NetworkManager Kdump: loaded Tainted: G I --------- --- 5.14.0-119.el9.x86_64 #1
Hardware name: Dell Inc. PowerEdge R740/06WXJT, BIOS 2.8.2 08/27/2020
RIP: 0010:vunmap+0x2e/0x30
...skip...
Call Trace:
__iommu_dma_free+0x96/0x100
efx_nic_free_buffer+0x2b/0x40 [sfc]
efx_ef10_try_update_nic_stats_vf+0x14a/0x1c0 [sfc]
efx_ef10_update_stats_vf+0x18/0x40 [sfc]
efx_start_all+0x15e/0x1d0 [sfc]
efx_net_open+0x5a/0xe0 [sfc]
__dev_open+0xe7/0x1a0
__dev_change_flags+0x1d7/0x240
dev_change_flags+0x21/0x60
...skip...
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
sfc: fix use after free when disabling sriov
Use after free is detected by kfence when disabling sriov. What was read
after being freed was vf->pci_dev: it was freed from pci_disable_sriov
and later read in efx_ef10_sriov_free_vf_vports, called from
efx_ef10_sriov_free_vf_vswitching.
Set the pointer to NULL at release time to not trying to read it later.
Reproducer and dmesg log (note that kfence doesn't detect it every time):
$ echo 1 > /sys/class/net/enp65s0f0np0/device/sriov_numvfs
$ echo 0 > /sys/class/net/enp65s0f0np0/device/sriov_numvfs
BUG: KFENCE: use-after-free read in efx_ef10_sriov_free_vf_vswitching+0x82/0x170 [sfc]
Use-after-free read at 0x00000000ff3c1ba5 (in kfence-#224):
efx_ef10_sriov_free_vf_vswitching+0x82/0x170 [sfc]
efx_ef10_pci_sriov_disable+0x38/0x70 [sfc]
efx_pci_sriov_configure+0x24/0x40 [sfc]
sriov_numvfs_store+0xfe/0x140
kernfs_fop_write_iter+0x11c/0x1b0
new_sync_write+0x11f/0x1b0
vfs_write+0x1eb/0x280
ksys_write+0x5f/0xe0
do_syscall_64+0x5c/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
kfence-#224: 0x00000000edb8ef95-0x00000000671f5ce1, size=2792, cache=kmalloc-4k
allocated by task 6771 on cpu 10 at 3137.860196s:
pci_alloc_dev+0x21/0x60
pci_iov_add_virtfn+0x2a2/0x320
sriov_enable+0x212/0x3e0
efx_ef10_sriov_configure+0x67/0x80 [sfc]
efx_pci_sriov_configure+0x24/0x40 [sfc]
sriov_numvfs_store+0xba/0x140
kernfs_fop_write_iter+0x11c/0x1b0
new_sync_write+0x11f/0x1b0
vfs_write+0x1eb/0x280
ksys_write+0x5f/0xe0
do_syscall_64+0x5c/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
freed by task 6771 on cpu 12 at 3170.991309s:
device_release+0x34/0x90
kobject_cleanup+0x3a/0x130
pci_iov_remove_virtfn+0xd9/0x120
sriov_disable+0x30/0xe0
efx_ef10_pci_sriov_disable+0x57/0x70 [sfc]
efx_pci_sriov_configure+0x24/0x40 [sfc]
sriov_numvfs_store+0xfe/0x140
kernfs_fop_write_iter+0x11c/0x1b0
new_sync_write+0x11f/0x1b0
vfs_write+0x1eb/0x280
ksys_write+0x5f/0xe0
do_syscall_64+0x5c/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
CVSS Score
7.8
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
igc: Reinstate IGC_REMOVED logic and implement it properly
The initially merged version of the igc driver code (via commit
146740f9abc4, "igc: Add support for PF") contained the following
IGC_REMOVED checks in the igc_rd32/wr32() MMIO accessors:
u32 igc_rd32(struct igc_hw *hw, u32 reg)
{
u8 __iomem *hw_addr = READ_ONCE(hw->hw_addr);
u32 value = 0;
if (IGC_REMOVED(hw_addr))
return ~value;
value = readl(&hw_addr[reg]);
/* reads should not return all F's */
if (!(~value) && (!reg || !(~readl(hw_addr))))
hw->hw_addr = NULL;
return value;
}
And:
#define wr32(reg, val) \
do { \
u8 __iomem *hw_addr = READ_ONCE((hw)->hw_addr); \
if (!IGC_REMOVED(hw_addr)) \
writel((val), &hw_addr[(reg)]); \
} while (0)
E.g. igb has similar checks in its MMIO accessors, and has a similar
macro E1000_REMOVED, which is implemented as follows:
#define E1000_REMOVED(h) unlikely(!(h))
These checks serve to detect and take note of an 0xffffffff MMIO read
return from the device, which can be caused by a PCIe link flap or some
other kind of PCI bus error, and to avoid performing MMIO reads and
writes from that point onwards.
However, the IGC_REMOVED macro was not originally implemented:
#ifndef IGC_REMOVED
#define IGC_REMOVED(a) (0)
#endif /* IGC_REMOVED */
This led to the IGC_REMOVED logic to be removed entirely in a
subsequent commit (commit 3c215fb18e70, "igc: remove IGC_REMOVED
function"), with the rationale that such checks matter only for
virtualization and that igc does not support virtualization -- but a
PCIe device can become detached even without virtualization being in
use, and without proper checks, a PCIe bus error affecting an igc
adapter will lead to various NULL pointer dereferences, as the first
access after the error will set hw->hw_addr to NULL, and subsequent
accesses will blindly dereference this now-NULL pointer.
This patch reinstates the IGC_REMOVED checks in igc_rd32/wr32(), and
implements IGC_REMOVED the way it is done for igb, by checking for the
unlikely() case of hw_addr being NULL. This change prevents the oopses
seen when a PCIe link flap occurs on an igc adapter.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
perf/core: Fix data race between perf_event_set_output() and perf_mmap_close()
Yang Jihing reported a race between perf_event_set_output() and
perf_mmap_close():
CPU1 CPU2
perf_mmap_close(e2)
if (atomic_dec_and_test(&e2->rb->mmap_count)) // 1 - > 0
detach_rest = true
ioctl(e1, IOC_SET_OUTPUT, e2)
perf_event_set_output(e1, e2)
...
list_for_each_entry_rcu(e, &e2->rb->event_list, rb_entry)
ring_buffer_attach(e, NULL);
// e1 isn't yet added and
// therefore not detached
ring_buffer_attach(e1, e2->rb)
list_add_rcu(&e1->rb_entry,
&e2->rb->event_list)
After this; e1 is attached to an unmapped rb and a subsequent
perf_mmap() will loop forever more:
again:
mutex_lock(&e->mmap_mutex);
if (event->rb) {
...
if (!atomic_inc_not_zero(&e->rb->mmap_count)) {
...
mutex_unlock(&e->mmap_mutex);
goto again;
}
}
The loop in perf_mmap_close() holds e2->mmap_mutex, while the attach
in perf_event_set_output() holds e1->mmap_mutex. As such there is no
serialization to avoid this race.
Change perf_event_set_output() to take both e1->mmap_mutex and
e2->mmap_mutex to alleviate that problem. Additionally, have the loop
in perf_mmap() detach the rb directly, this avoids having to wait for
the concurrent perf_mmap_close() to get around to doing it to make
progress.
CVSS Score
4.7
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
pinctrl: ralink: Check for null return of devm_kcalloc
Because of the possible failure of the allocation, data->domains might
be NULL pointer and will cause the dereference of the NULL pointer
later.
Therefore, it might be better to check it and directly return -ENOMEM
without releasing data manually if fails, because the comment of the
devm_kmalloc() says "Memory allocated with this function is
automatically freed on driver detach.".
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
power/reset: arm-versatile: Fix refcount leak in versatile_reboot_probe
of_find_matching_node_and_match() returns a node pointer with refcount
incremented, we should use of_node_put() on it when not need anymore.
Add missing of_node_put() to avoid refcount leak.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
KVM: VMX: Prevent RSB underflow before vmenter
On VMX, there are some balanced returns between the time the guest's
SPEC_CTRL value is written, and the vmenter.
Balanced returns (matched by a preceding call) are usually ok, but it's
at least theoretically possible an NMI with a deep call stack could
empty the RSB before one of the returns.
For maximum paranoia, don't allow *any* returns (balanced or otherwise)
between the SPEC_CTRL write and the vmenter.
[ bp: Fix 32-bit build. ]
CVSS Score
5.5
EPSS Score
0.001
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
x86/speculation: Fill RSB on vmexit for IBRS
Prevent RSB underflow/poisoning attacks with RSB. While at it, add a
bunch of comments to attempt to document the current state of tribal
knowledge about RSB attacks and what exactly is being mitigated.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26