Security Vulnerabilities
- CVEs Published In May 2024
In the Linux kernel, the following vulnerability has been resolved:
net: batman-adv: fix error handling
Syzbot reported ODEBUG warning in batadv_nc_mesh_free(). The problem was
in wrong error handling in batadv_mesh_init().
Before this patch batadv_mesh_init() was calling batadv_mesh_free() in case
of any batadv_*_init() calls failure. This approach may work well, when
there is some kind of indicator, which can tell which parts of batadv are
initialized; but there isn't any.
All written above lead to cleaning up uninitialized fields. Even if we hide
ODEBUG warning by initializing bat_priv->nc.work, syzbot was able to hit
GPF in batadv_nc_purge_paths(), because hash pointer in still NULL. [1]
To fix these bugs we can unwind batadv_*_init() calls one by one.
It is good approach for 2 reasons: 1) It fixes bugs on error handling
path 2) It improves the performance, since we won't call unneeded
batadv_*_free() functions.
So, this patch makes all batadv_*_init() clean up all allocated memory
before returning with an error to no call correspoing batadv_*_free()
and open-codes batadv_mesh_free() with proper order to avoid touching
uninitialized fields.
In the Linux kernel, the following vulnerability has been resolved:
regmap: Fix possible double-free in regcache_rbtree_exit()
In regcache_rbtree_insert_to_block(), when 'present' realloc failed,
the 'blk' which is supposed to assign to 'rbnode->block' will be freed,
so 'rbnode->block' points a freed memory, in the error handling path of
regcache_rbtree_init(), 'rbnode->block' will be freed again in
regcache_rbtree_exit(), KASAN will report double-free as follows:
BUG: KASAN: double-free or invalid-free in kfree+0xce/0x390
Call Trace:
slab_free_freelist_hook+0x10d/0x240
kfree+0xce/0x390
regcache_rbtree_exit+0x15d/0x1a0
regcache_rbtree_init+0x224/0x2c0
regcache_init+0x88d/0x1310
__regmap_init+0x3151/0x4a80
__devm_regmap_init+0x7d/0x100
madera_spi_probe+0x10f/0x333 [madera_spi]
spi_probe+0x183/0x210
really_probe+0x285/0xc30
To fix this, moving up the assignment of rbnode->block to immediately after
the reallocation has succeeded so that the data structure stays valid even
if the second reallocation fails.
In the Linux kernel, the following vulnerability has been resolved:
octeontx2-af: Fix possible null pointer dereference.
This patch fixes possible null pointer dereference in files
"rvu_debugfs.c" and "rvu_nix.c"
In the Linux kernel, the following vulnerability has been resolved:
IB/qib: Protect from buffer overflow in struct qib_user_sdma_pkt fields
Overflowing either addrlimit or bytes_togo can allow userspace to trigger
a buffer overflow of kernel memory. Check for overflows in all the places
doing math on user controlled buffers.
In the Linux kernel, the following vulnerability has been resolved:
riscv, bpf: Fix potential NULL dereference
The bpf_jit_binary_free() function requires a non-NULL argument. When
the RISC-V BPF JIT fails to converge in NR_JIT_ITERATIONS steps,
jit_data->header will be NULL, which triggers a NULL
dereference. Avoid this by checking the argument, prior calling the
function.
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: Fix even more out of bound writes from debugfs
CVE-2021-42327 was fixed by:
commit f23750b5b3d98653b31d4469592935ef6364ad67
Author: Thelford Williams <tdwilliamsiv@gmail.com>
Date: Wed Oct 13 16:04:13 2021 -0400
drm/amdgpu: fix out of bounds write
but amdgpu_dm_debugfs.c contains more of the same issue so fix the
remaining ones.
v2:
* Add missing fix in dp_max_bpc_write (Harry Wentland)
In the Linux kernel, the following vulnerability has been resolved:
drm/ttm: fix memleak in ttm_transfered_destroy
We need to cleanup the fences for ghost objects as well.
Bug: https://bugzilla.kernel.org/show_bug.cgi?id=214029
Bug: https://bugzilla.kernel.org/show_bug.cgi?id=214447
In the Linux kernel, the following vulnerability has been resolved:
mm: khugepaged: skip huge page collapse for special files
The read-only THP for filesystems will collapse THP for files opened
readonly and mapped with VM_EXEC. The intended usecase is to avoid TLB
misses for large text segments. But it doesn't restrict the file types
so a THP could be collapsed for a non-regular file, for example, block
device, if it is opened readonly and mapped with EXEC permission. This
may cause bugs, like [1] and [2].
This is definitely not the intended usecase, so just collapse THP for
regular files in order to close the attack surface.
[shy828301@gmail.com: fix vm_file check [3]]
In the Linux kernel, the following vulnerability has been resolved:
comedi: vmk80xx: fix bulk-buffer overflow
The driver is using endpoint-sized buffers but must not assume that the
tx and rx buffers are of equal size or a malicious device could overflow
the slab-allocated receive buffer when doing bulk transfers.
In the Linux kernel, the following vulnerability has been resolved:
comedi: vmk80xx: fix transfer-buffer overflows
The driver uses endpoint-sized USB transfer buffers but up until
recently had no sanity checks on the sizes.
Commit e1f13c879a7c ("staging: comedi: check validity of wMaxPacketSize
of usb endpoints found") inadvertently fixed NULL-pointer dereferences
when accessing the transfer buffers in case a malicious device has a
zero wMaxPacketSize.
Make sure to allocate buffers large enough to handle also the other
accesses that are done without a size check (e.g. byte 18 in
vmk80xx_cnt_insn_read() for the VMK8061_MODEL) to avoid writing beyond
the buffers, for example, when doing descriptor fuzzing.
The original driver was for a low-speed device with 8-byte buffers.
Support was later added for a device that uses bulk transfers and is
presumably a full-speed device with a maximum 64-byte wMaxPacketSize.