In the Linux kernel, the following vulnerability has been resolved:
i40e: Fix potential invalid access when MAC list is empty
list_first_entry() never returns NULL - if the list is empty, it still
returns a pointer to an invalid object, leading to potential invalid
memory access when dereferenced.
Fix this by using list_first_entry_or_null instead of list_first_entry.
In the Linux kernel, the following vulnerability has been resolved:
pcmcia: Fix a NULL pointer dereference in __iodyn_find_io_region()
In __iodyn_find_io_region(), pcmcia_make_resource() is assigned to
res and used in pci_bus_alloc_resource(). There is a dereference of res
in pci_bus_alloc_resource(), which could lead to a NULL pointer
dereference on failure of pcmcia_make_resource().
Fix this bug by adding a check of res.
In the Linux kernel, the following vulnerability has been resolved:
ppp: fix memory leak in pad_compress_skb
If alloc_skb() fails in pad_compress_skb(), it returns NULL without
releasing the old skb. The caller does:
skb = pad_compress_skb(ppp, skb);
if (!skb)
goto drop;
drop:
kfree_skb(skb);
When pad_compress_skb() returns NULL, the reference to the old skb is
lost and kfree_skb(skb) ends up doing nothing, leading to a memory leak.
Align pad_compress_skb() semantics with realloc(): only free the old
skb if allocation and compression succeed. At the call site, use the
new_skb variable so the original skb is not lost when pad_compress_skb()
fails.
In the Linux kernel, the following vulnerability has been resolved:
ax25: properly unshare skbs in ax25_kiss_rcv()
Bernard Pidoux reported a regression apparently caused by commit
c353e8983e0d ("net: introduce per netns packet chains").
skb->dev becomes NULL and we crash in __netif_receive_skb_core().
Before above commit, different kind of bugs or corruptions could happen
without a major crash.
But the root cause is that ax25_kiss_rcv() can queue/mangle input skb
without checking if this skb is shared or not.
Many thanks to Bernard Pidoux for his help, diagnosis and tests.
We had a similar issue years ago fixed with commit 7aaed57c5c28
("phonet: properly unshare skbs in phonet_rcv()").
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: fix OOB read/write in network-coding decode
batadv_nc_skb_decode_packet() trusts coded_len and checks only against
skb->len. XOR starts at sizeof(struct batadv_unicast_packet), reducing
payload headroom, and the source skb length is not verified, allowing an
out-of-bounds read and a small out-of-bounds write.
Validate that coded_len fits within the payload area of both destination
and source sk_buffs before XORing.
In the Linux kernel, the following vulnerability has been resolved:
f2fs: don't reset unchangable mount option in f2fs_remount()
syzbot reports a bug as below:
general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] PREEMPT SMP KASAN
RIP: 0010:__lock_acquire+0x69/0x2000 kernel/locking/lockdep.c:4942
Call Trace:
lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5691
__raw_write_lock include/linux/rwlock_api_smp.h:209 [inline]
_raw_write_lock+0x2e/0x40 kernel/locking/spinlock.c:300
__drop_extent_tree+0x3ac/0x660 fs/f2fs/extent_cache.c:1100
f2fs_drop_extent_tree+0x17/0x30 fs/f2fs/extent_cache.c:1116
f2fs_insert_range+0x2d5/0x3c0 fs/f2fs/file.c:1664
f2fs_fallocate+0x4e4/0x6d0 fs/f2fs/file.c:1838
vfs_fallocate+0x54b/0x6b0 fs/open.c:324
ksys_fallocate fs/open.c:347 [inline]
__do_sys_fallocate fs/open.c:355 [inline]
__se_sys_fallocate fs/open.c:353 [inline]
__x64_sys_fallocate+0xbd/0x100 fs/open.c:353
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The root cause is race condition as below:
- since it tries to remount rw filesystem, so that do_remount won't
call sb_prepare_remount_readonly to block fallocate, there may be race
condition in between remount and fallocate.
- in f2fs_remount(), default_options() will reset mount option to default
one, and then update it based on result of parse_options(), so there is
a hole which race condition can happen.
Thread A Thread B
- f2fs_fill_super
- parse_options
- clear_opt(READ_EXTENT_CACHE)
- f2fs_remount
- default_options
- set_opt(READ_EXTENT_CACHE)
- f2fs_fallocate
- f2fs_insert_range
- f2fs_drop_extent_tree
- __drop_extent_tree
- __may_extent_tree
- test_opt(READ_EXTENT_CACHE) return true
- write_lock(&et->lock) access NULL pointer
- parse_options
- clear_opt(READ_EXTENT_CACHE)
In the Linux kernel, the following vulnerability has been resolved:
mfd: arizona: Use pm_runtime_resume_and_get() to prevent refcnt leak
In arizona_clk32k_enable(), we should use pm_runtime_resume_and_get()
as pm_runtime_get_sync() will increase the refcnt even when it
returns an error.
In the Linux kernel, the following vulnerability has been resolved:
PCI/ASPM: Disable ASPM on MFD function removal to avoid use-after-free
Struct pcie_link_state->downstream is a pointer to the pci_dev of function
0. Previously we retained that pointer when removing function 0, and
subsequent ASPM policy changes dereferenced it, resulting in a
use-after-free warning from KASAN, e.g.:
# echo 1 > /sys/bus/pci/devices/0000:03:00.0/remove
# echo powersave > /sys/module/pcie_aspm/parameters/policy
BUG: KASAN: slab-use-after-free in pcie_config_aspm_link+0x42d/0x500
Call Trace:
kasan_report+0xae/0xe0
pcie_config_aspm_link+0x42d/0x500
pcie_aspm_set_policy+0x8e/0x1a0
param_attr_store+0x162/0x2c0
module_attr_store+0x3e/0x80
PCIe spec r6.0, sec 7.5.3.7, recommends that software program the same ASPM
Control value in all functions of multi-function devices.
Disable ASPM and free the pcie_link_state when any child function is
removed so we can discard the dangling pcie_link_state->downstream pointer
and maintain the same ASPM Control configuration for all functions.
[bhelgaas: commit log and comment]
In the Linux kernel, the following vulnerability has been resolved:
scsi: ses: Handle enclosure with just a primary component gracefully
This reverts commit 3fe97ff3d949 ("scsi: ses: Don't attach if enclosure
has no components") and introduces proper handling of case where there are
no detected secondary components, but primary component (enumerated in
num_enclosures) does exist. That fix was originally proposed by Ding Hui
<dinghui@sangfor.com.cn>.
Completely ignoring devices that have one primary enclosure and no
secondary one results in ses_intf_add() bailing completely
scsi 2:0:0:254: enclosure has no enumerated components
scsi 2:0:0:254: Failed to bind enclosure -12ven in valid configurations such
even on valid configurations with 1 primary and 0 secondary enclosures as
below:
# sg_ses /dev/sg0
3PARdata SES 3321
Supported diagnostic pages:
Supported Diagnostic Pages [sdp] [0x0]
Configuration (SES) [cf] [0x1]
Short Enclosure Status (SES) [ses] [0x8]
# sg_ses -p cf /dev/sg0
3PARdata SES 3321
Configuration diagnostic page:
number of secondary subenclosures: 0
generation code: 0x0
enclosure descriptor list
Subenclosure identifier: 0 [primary]
relative ES process id: 0, number of ES processes: 1
number of type descriptor headers: 1
enclosure logical identifier (hex): 20000002ac02068d
enclosure vendor: 3PARdata product: VV rev: 3321
type descriptor header and text list
Element type: Unspecified, subenclosure id: 0
number of possible elements: 1
The changelog for the original fix follows
=====
We can get a crash when disconnecting the iSCSI session,
the call trace like this:
[ffff00002a00fb70] kfree at ffff00000830e224
[ffff00002a00fba0] ses_intf_remove at ffff000001f200e4
[ffff00002a00fbd0] device_del at ffff0000086b6a98
[ffff00002a00fc50] device_unregister at ffff0000086b6d58
[ffff00002a00fc70] __scsi_remove_device at ffff00000870608c
[ffff00002a00fca0] scsi_remove_device at ffff000008706134
[ffff00002a00fcc0] __scsi_remove_target at ffff0000087062e4
[ffff00002a00fd10] scsi_remove_target at ffff0000087064c0
[ffff00002a00fd70] __iscsi_unbind_session at ffff000001c872c4
[ffff00002a00fdb0] process_one_work at ffff00000810f35c
[ffff00002a00fe00] worker_thread at ffff00000810f648
[ffff00002a00fe70] kthread at ffff000008116e98
In ses_intf_add, components count could be 0, and kcalloc 0 size scomp,
but not saved in edev->component[i].scratch
In this situation, edev->component[0].scratch is an invalid pointer,
when kfree it in ses_intf_remove_enclosure, a crash like above would happen
The call trace also could be other random cases when kfree cannot catch
the invalid pointer
We should not use edev->component[] array when the components count is 0
We also need check index when use edev->component[] array in
ses_enclosure_data_process
=====