In the Linux kernel, the following vulnerability has been resolved:
qede: confirm skb is allocated before using
qede_build_skb() assumes build_skb() always works and goes straight
to skb_reserve(). However, build_skb() can fail under memory pressure.
This results in a kernel panic because the skb to reserve is NULL.
Add a check in case build_skb() failed to allocate and return NULL.
The NULL return is handled correctly in callers to qede_build_skb().
mm/mempolicy: fix mpol_new leak in shared_policy_replace
In the Linux kernel, the following vulnerability has been resolved:
mm/mempolicy: fix mpol_new leak in shared_policy_replace
If mpol_new is allocated but not used in restart loop, mpol_new will be
freed via mpol_put before returning to the caller. But refcnt is not
initialized yet, so mpol_put could not do the right things and might
leak the unused mpol_new. This would happen if mempolicy was updated on
the shared shmem file while the sp->lock has been dropped during the
memory allocation.
This issue could be triggered easily with the below code snippet if
there are many processes doing the below work at the same time:
shmid = shmget(
lz4: fix LZ4_decompress_safe_partial read out of bound
In the Linux kernel, the following vulnerability has been resolved:
lz4: fix LZ4_decompress_safe_partial read out of bound
When partialDecoding, it is EOF if we've either filled the output buffer
or can't proceed with reading an offset for following match.
In some extreme corner cases when compressed data is suitably corrupted,
UAF will occur. As reported by KASAN [1], LZ4_decompress_safe_partial
may lead to read out of bound problem during decoding. lz4 upstream has
fixed it [2] and this issue has been disscussed here [3] before.
current decompression routine was ported from lz4 v1.8.3, bumping
lib/lz4 to v1.9.+ is certainly a huge wor
mmmremap.c: avoid pointless invalidate_range_start/end on mremap(old_size=0)
In the Linux kernel, the following vulnerability has been resolved:
mmmremap.c: avoid pointless invalidate_range_start/end on mremap(old_size=0)
If an mremap() syscall with old_size=0 ends up in move_page_tables(), it
will call invalidate_range_start()/invalidate_range_end() unnecessarily,
i.e. with an empty range.
This causes a WARN in KVM's mmu_notifier. In the past, empty ranges
have been diagnosed to be off-by-one bugs, hence the WARNing. Given the
low (so far) number of unique reports, the benefits of detecting more
buggy callers seem to outweigh the cost of having to fix cases such as
this one, where userspace is doing something s
btrfs: fix qgroup reserve overflow the qgroup limit
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix qgroup reserve overflow the qgroup limit
We use extent_changeset->bytes_changed in qgroup_reserve_data() to record
how many bytes we set for EXTENT_QGROUP_RESERVED state. Currently the
bytes_changed is set as "unsigned int", and it will overflow if we try to
fallocate a range larger than 4GiB. The result is we reserve less bytes
and eventually break the qgroup limit.
Unlike regular buffered/direct write, which we use one changeset for
each ordered extent, which can never be larger than 256M. For
fallocate, we use one changeset for the whole range, thus it no lo
In the Linux kernel, the following vulnerability has been resolved:
irqchip/gic-v3: Fix GICR_CTLR.RWP polling
It turns out that our polling of RWP is totally wrong when checking
for it in the redistributors, as we test the *distributor* bit index,
whereas it is a different bit number in the RDs... Oopsie boo.
This is embarassing. Not only because it is wrong, but also because
it took *8 years* to notice the blunder...
Just fix the damn thing.
In the Linux kernel, the following vulnerability has been resolved:
ata: sata_dwc_460ex: Fix crash due to OOB write
the driver uses libata's "tag" values from in various arrays.
Since the mentioned patch bumped the ATA_TAG_INTERNAL to 32,
the value of the SATA_DWC_QCMD_MAX needs to account for that.
Otherwise ATA_TAG_INTERNAL usage cause similar crashes like
this as reported by Tice Rex on the OpenWrt Forum and
reproduced (with symbols) here:
| BUG: Kernel NULL pointer dereference at 0x00000000
| Faulting instruction address: 0xc03ed4b8
| Oops: Kernel access of bad area, sig: 11 [#1]
| BE PAGE_SIZE=4K PowerPC 44x Platform
| CPU: 0 PID: 36
powerpc: Fix virt_addr_valid() for 64-bit Book3E & 32-bit
In the Linux kernel, the following vulnerability has been resolved:
powerpc: Fix virt_addr_valid() for 64-bit Book3E & 32-bit
mpe: On 64-bit Book3E vmalloc space starts at 0x8000000000000000.
Because of the way __pa() works we have:
__pa(0x8000000000000000) == 0, and therefore
virt_to_pfn(0x8000000000000000) == 0, and therefore
virt_addr_valid(0x8000000000000000) == true
Which is wrong, virt_addr_valid() should be false for vmalloc space.
In fact all vmalloc addresses that alias with a valid PFN will return
true from virt_addr_valid(). That can cause bugs with hardened usercopy
as described below by Kefeng Wang:
When running etht
In the Linux kernel, the following vulnerability has been resolved:
veth: Ensure eth header is in skb's linear part
After feeding a decapsulated packet to a veth device with act_mirred,
skb_headlen() may be 0. But veth_xmit() calls __dev_forward_skb(),
which expects at least ETH_HLEN byte of linear data (as
__dev_forward_skb2() calls eth_type_trans(), which pulls ETH_HLEN bytes
unconditionally).
Use pskb_may_pull() to ensure veth_xmit() respects this constraint.
kernel BUG at include/linux/skbuff.h:2328!
RIP: 0010:eth_type_trans+0xcf/0x140
Call Trace:
<IRQ>
__dev_forward_skb2+0xe3/0x160
veth_xmit+0x6e/0x250 [veth]
dev_hard_start_xmit+
net: ethernet: stmmac: fix altr_tse_pcs function when using a fixed-link
In the Linux kernel, the following vulnerability has been resolved:
net: ethernet: stmmac: fix altr_tse_pcs function when using a fixed-link
When using a fixed-link, the altr_tse_pcs driver crashes
due to null-pointer dereference as no phy_device is provided to
tse_pcs_fix_mac_speed function. Fix this by adding a check for
phy_dev before calling the tse_pcs_fix_mac_speed() function.
Also clean up the tse_pcs_fix_mac_speed function a bit. There is
no need to check for splitter_base and sgmii_adapter_base
because the driver will fail if these 2 variables are not
derived from the device tree.
net/smc: Fix NULL pointer dereference in smc_pnet_find_ib()
In the Linux kernel, the following vulnerability has been resolved:
net/smc: Fix NULL pointer dereference in smc_pnet_find_ib()
dev_name() was called with dev.parent as argument but without to
NULL-check it before.
Solve this by checking the pointer before the call to dev_name().
In the Linux kernel, the following vulnerability has been resolved:
nfc: nci: add flush_workqueue to prevent uaf
Our detector found a concurrent use-after-free bug when detaching an
NCI device. The main reason for this bug is the unexpected scheduling
between the used delayed mechanism (timer and workqueue).
The race can be demonstrated below:
Thread-1 Thread-2
| nci_dev_up()
| nci_open_device()
| __nci_request(nci_reset_req)
| nci_send_cmd
cifs: potential buffer overflow in handling symlinks
In the Linux kernel, the following vulnerability has been resolved:
cifs: potential buffer overflow in handling symlinks
Smatch printed a warning:
arch/x86/crypto/poly1305_glue.c:198 poly1305_update_arch() error:
__memcpy() 'dctx->buf' too small (16 vs u32max)
It's caused because Smatch marks 'link_len' as untrusted since it comes
from sscanf(). Add a check to ensure that 'link_len' is not larger than
the size of the 'link_str' buffer.
drm/amdkfd: Check for potential null return of kmalloc_array()
In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Check for potential null return of kmalloc_array()
As the kmalloc_array() may return null, the 'event_waiters[i].wait' would lead to null-pointer dereference.
Therefore, it is better to check the return value of kmalloc_array() to avoid this confusion.
In the Linux kernel, the following vulnerability has been resolved:
scsi: target: tcmu: Fix possible page UAF
tcmu_try_get_data_page() looks up pages under cmdr_lock, but it does not
take refcount properly and just returns page pointer. When
tcmu_try_get_data_page() returns, the returned page may have been freed by
tcmu_blocks_release().
We need to get_page() under cmdr_lock to avoid concurrent
tcmu_blocks_release().
mm: fix unexpected zeroed page mapping with zram swap
In the Linux kernel, the following vulnerability has been resolved:
mm: fix unexpected zeroed page mapping with zram swap
Two processes under CLONE_VM cloning, user process can be corrupted by
seeing zeroed page unexpectedly.
CPU A CPU B
do_swap_page do_swap_page
SWP_SYNCHRONOUS_IO path SWP_SYNCHRONOUS_IO path
swap_readpage valid data
swap_slot_free_notify
delete zram entry
swap_readpage zeroed(invalid) data
pte_lock
map the *zero data* to userspace
pte_unlo
net: usb: aqc111: Fix out-of-bounds accesses in RX fixup
In the Linux kernel, the following vulnerability has been resolved:
net: usb: aqc111: Fix out-of-bounds accesses in RX fixup
aqc111_rx_fixup() contains several out-of-bounds accesses that can be
triggered by a malicious (or defective) USB device, in particular:
- The metadata array (desc_offset..desc_offset+2*pkt_count) can be out of bounds,
causing OOB reads and (on big-endian systems) OOB endianness flips.
- A packet can overlap the metadata array, causing a later OOB
endianness flip to corrupt data used by a cloned SKB that has already
been handed off into the network stack.
- A packet SKB can be constructed whose tail is fa
ipv6: fix panic when forwarding a pkt with no in6 dev
In the Linux kernel, the following vulnerability has been resolved:
ipv6: fix panic when forwarding a pkt with no in6 dev
kongweibin reported a kernel panic in ip6_forward() when input interface
has no in6 dev associated.
The following tc commands were used to reproduce this panic:
tc qdisc del dev vxlan100 root
tc qdisc add dev vxlan100 root netem corrupt 5%
dm integrity: fix memory corruption when tag_size is less than digest size
In the Linux kernel, the following vulnerability has been resolved:
dm integrity: fix memory corruption when tag_size is less than digest size
It is possible to set up dm-integrity in such a way that the
"tag_size" parameter is less than the actual digest size. In this
situation, a part of the digest beyond tag_size is ignored.
In this case, dm-integrity would write beyond the end of the
ic->recalc_tags array and corrupt memory. The corruption happened in
integrity_recalc->integrity_sector_checksum->crypto_shash_final.
Fix this corruption by increasing the tags array so that it has enough
padding at the end to accomodate the loop in integ
jffs2: fix use-after-free in jffs2_clear_xattr_subsystem
In the Linux kernel, the following vulnerability has been resolved:
jffs2: fix use-after-free in jffs2_clear_xattr_subsystem
When we mount a jffs2 image, assume that the first few blocks of
the image are normal and contain at least one xattr-related inode,
but the next block is abnormal. As a result, an error is returned
in jffs2_scan_eraseblock(). jffs2_clear_xattr_subsystem() is then
called in jffs2_build_filesystem() and then again in
jffs2_do_fill_super().
Finally we can observe the following report:
==================================================================
BUG: KASAN: use-after-free in jffs2_clear_xattr_subsystem+0x95/0x6ac