In the Linux kernel, the following vulnerability has been resolved:
nfsd: make sure exp active before svc_export_show
The function `e_show` was called with protection from RCU. This only
ensures that `exp` will not be freed. Therefore, the reference count for
`exp` can drop to zero, which will trigger a refcount use-after-free
warning when `exp_get` is called. To resolve this issue, use
`cache_get_rcu` to ensure that `exp` remains active.
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 3 PID: 819 at lib/refcount.c:25
refcount_warn_saturate+0xb1/0x120
CPU: 3 UID: 0 PID: 819 Comm: cat Not tainted 6.12.0-rc3+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
RIP: 0010:refcount_warn_saturate+0xb1/0x120
...
Call Trace:
<TASK>
e_show+0x20b/0x230 [nfsd]
seq_read_iter+0x589/0x770
seq_read+0x1e5/0x270
vfs_read+0x125/0x530
ksys_read+0xc1/0x160
do_syscall_64+0x5f/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
In the Linux kernel, the following vulnerability has been resolved:
udmabuf: change folios array from kmalloc to kvmalloc
When PAGE_SIZE 4096, MAX_PAGE_ORDER 10, 64bit machine,
page_alloc only support 4MB.
If above this, trigger this warn and return NULL.
udmabuf can change size limit, if change it to 3072(3GB), and then alloc
3GB udmabuf, will fail create.
[ 4080.876581] ------------[ cut here ]------------
[ 4080.876843] WARNING: CPU: 3 PID: 2015 at mm/page_alloc.c:4556 __alloc_pages+0x2c8/0x350
[ 4080.878839] RIP: 0010:__alloc_pages+0x2c8/0x350
[ 4080.879470] Call Trace:
[ 4080.879473] <TASK>
[ 4080.879473] ? __alloc_pages+0x2c8/0x350
[ 4080.879475] ? __warn.cold+0x8e/0xe8
[ 4080.880647] ? __alloc_pages+0x2c8/0x350
[ 4080.880909] ? report_bug+0xff/0x140
[ 4080.881175] ? handle_bug+0x3c/0x80
[ 4080.881556] ? exc_invalid_op+0x17/0x70
[ 4080.881559] ? asm_exc_invalid_op+0x1a/0x20
[ 4080.882077] ? udmabuf_create+0x131/0x400
Because MAX_PAGE_ORDER, kmalloc can max alloc 4096 * (1 << 10), 4MB
memory, each array entry is pointer(8byte), so can save 524288 pages(2GB).
Further more, costly order(order 3) may not be guaranteed that it can be
applied for, due to fragmentation.
This patch change udmabuf array use kvmalloc_array, this can fallback
alloc into vmalloc, which can guarantee allocation for any size and does
not affect the performance of kmalloc allocations.
In the Linux kernel, the following vulnerability has been resolved:
drivers: soc: xilinx: add the missing kfree in xlnx_add_cb_for_suspend()
If we fail to allocate memory for cb_data by kmalloc, the memory
allocation for eve_data is never freed, add the missing kfree()
in the error handling path.
In the Linux kernel, the following vulnerability has been resolved:
hfsplus: don't query the device logical block size multiple times
Devices block sizes may change. One of these cases is a loop device by
using ioctl LOOP_SET_BLOCK_SIZE.
While this may cause other issues like IO being rejected, in the case of
hfsplus, it will allocate a block by using that size and potentially write
out-of-bounds when hfsplus_read_wrapper calls hfsplus_submit_bio and the
latter function reads a different io_size.
Using a new min_io_size initally set to sb_min_blocksize works for the
purposes of the original fix, since it will be set to the max between
HFSPLUS_SECTOR_SIZE and the first seen logical block size. We still use the
max between HFSPLUS_SECTOR_SIZE and min_io_size in case the latter is not
initialized.
Tested by mounting an hfsplus filesystem with loop block sizes 512, 1024
and 4096.
The produced KASAN report before the fix looks like this:
[ 419.944641] ==================================================================
[ 419.945655] BUG: KASAN: slab-use-after-free in hfsplus_read_wrapper+0x659/0xa0a
[ 419.946703] Read of size 2 at addr ffff88800721fc00 by task repro/10678
[ 419.947612]
[ 419.947846] CPU: 0 UID: 0 PID: 10678 Comm: repro Not tainted 6.12.0-rc5-00008-gdf56e0f2f3ca #84
[ 419.949007] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
[ 419.950035] Call Trace:
[ 419.950384] <TASK>
[ 419.950676] dump_stack_lvl+0x57/0x78
[ 419.951212] ? hfsplus_read_wrapper+0x659/0xa0a
[ 419.951830] print_report+0x14c/0x49e
[ 419.952361] ? __virt_addr_valid+0x267/0x278
[ 419.952979] ? kmem_cache_debug_flags+0xc/0x1d
[ 419.953561] ? hfsplus_read_wrapper+0x659/0xa0a
[ 419.954231] kasan_report+0x89/0xb0
[ 419.954748] ? hfsplus_read_wrapper+0x659/0xa0a
[ 419.955367] hfsplus_read_wrapper+0x659/0xa0a
[ 419.955948] ? __pfx_hfsplus_read_wrapper+0x10/0x10
[ 419.956618] ? do_raw_spin_unlock+0x59/0x1a9
[ 419.957214] ? _raw_spin_unlock+0x1a/0x2e
[ 419.957772] hfsplus_fill_super+0x348/0x1590
[ 419.958355] ? hlock_class+0x4c/0x109
[ 419.958867] ? __pfx_hfsplus_fill_super+0x10/0x10
[ 419.959499] ? __pfx_string+0x10/0x10
[ 419.960006] ? lock_acquire+0x3e2/0x454
[ 419.960532] ? bdev_name.constprop.0+0xce/0x243
[ 419.961129] ? __pfx_bdev_name.constprop.0+0x10/0x10
[ 419.961799] ? pointer+0x3f0/0x62f
[ 419.962277] ? __pfx_pointer+0x10/0x10
[ 419.962761] ? vsnprintf+0x6c4/0xfba
[ 419.963178] ? __pfx_vsnprintf+0x10/0x10
[ 419.963621] ? setup_bdev_super+0x376/0x3b3
[ 419.964029] ? snprintf+0x9d/0xd2
[ 419.964344] ? __pfx_snprintf+0x10/0x10
[ 419.964675] ? lock_acquired+0x45c/0x5e9
[ 419.965016] ? set_blocksize+0x139/0x1c1
[ 419.965381] ? sb_set_blocksize+0x6d/0xae
[ 419.965742] ? __pfx_hfsplus_fill_super+0x10/0x10
[ 419.966179] mount_bdev+0x12f/0x1bf
[ 419.966512] ? __pfx_mount_bdev+0x10/0x10
[ 419.966886] ? vfs_parse_fs_string+0xce/0x111
[ 419.967293] ? __pfx_vfs_parse_fs_string+0x10/0x10
[ 419.967702] ? __pfx_hfsplus_mount+0x10/0x10
[ 419.968073] legacy_get_tree+0x104/0x178
[ 419.968414] vfs_get_tree+0x86/0x296
[ 419.968751] path_mount+0xba3/0xd0b
[ 419.969157] ? __pfx_path_mount+0x10/0x10
[ 419.969594] ? kmem_cache_free+0x1e2/0x260
[ 419.970311] do_mount+0x99/0xe0
[ 419.970630] ? __pfx_do_mount+0x10/0x10
[ 419.971008] __do_sys_mount+0x199/0x1c9
[ 419.971397] do_syscall_64+0xd0/0x135
[ 419.971761] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 419.972233] RIP: 0033:0x7c3cb812972e
[ 419.972564] Code: 48 8b 0d f5 46 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d c2 46 0d 00 f7 d8 64 89 01 48
[ 419.974371] RSP: 002b:00007ffe30632548 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
[ 419.975048] RAX: ffffffffffffffda RBX: 00007ffe306328d8 RCX: 00007c3cb812972e
[ 419.975701] RDX: 0000000020000000 RSI: 0000000020000c80 RDI:
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: Fix NULL pointer dereference in object->file
At present, the object->file has the NULL pointer dereference problem in
ondemand-mode. The root cause is that the allocated fd and object->file
lifetime are inconsistent, and the user-space invocation to anon_fd uses
object->file. Following is the process that triggers the issue:
[write fd] [umount]
cachefiles_ondemand_fd_write_iter
fscache_cookie_state_machine
cachefiles_withdraw_cookie
if (!file) return -ENOBUFS
cachefiles_clean_up_object
cachefiles_unmark_inode_in_use
fput(object->file)
object->file = NULL
// file NULL pointer dereference!
__cachefiles_write(..., file, ...)
Fix this issue by add an additional reference count to the object->file
before write/llseek, and decrement after it finished.
In the Linux kernel, the following vulnerability has been resolved:
drm: zynqmp_kms: Unplug DRM device before removal
Prevent userspace accesses to the DRM device from causing
use-after-frees by unplugging the device before we remove it. This
causes any further userspace accesses to result in an error without
further calls into this driver's internals.
In the Linux kernel, the following vulnerability has been resolved:
wifi: mwifiex: Fix memcpy() field-spanning write warning in mwifiex_config_scan()
Replace one-element array with a flexible-array member in `struct
mwifiex_ie_types_wildcard_ssid_params` to fix the following warning
on a MT8173 Chromebook (mt8173-elm-hana):
[ 356.775250] ------------[ cut here ]------------
[ 356.784543] memcpy: detected field-spanning write (size 6) of single field "wildcard_ssid_tlv->ssid" at drivers/net/wireless/marvell/mwifiex/scan.c:904 (size 1)
[ 356.813403] WARNING: CPU: 3 PID: 742 at drivers/net/wireless/marvell/mwifiex/scan.c:904 mwifiex_scan_networks+0x4fc/0xf28 [mwifiex]
The "(size 6)" above is exactly the length of the SSID of the network
this device was connected to. The source of the warning looks like:
ssid_len = user_scan_in->ssid_list[i].ssid_len;
[...]
memcpy(wildcard_ssid_tlv->ssid,
user_scan_in->ssid_list[i].ssid, ssid_len);
There is a #define WILDCARD_SSID_TLV_MAX_SIZE that uses sizeof() on this
struct, but it already didn't account for the size of the one-element
array, so it doesn't need to be changed.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: 6fire: Release resources at card release
The current 6fire code tries to release the resources right after the
call of usb6fire_chip_abort(). But at this moment, the card object
might be still in use (as we're calling snd_card_free_when_closed()).
For avoid potential UAFs, move the release of resources to the card's
private_free instead of the manual call of usb6fire_chip_destroy() at
the USB disconnect callback.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: caiaq: Use snd_card_free_when_closed() at disconnection
The USB disconnect callback is supposed to be short and not too-long
waiting. OTOH, the current code uses snd_card_free() at
disconnection, but this waits for the close of all used fds, hence it
can take long. It eventually blocks the upper layer USB ioctls, which
may trigger a soft lockup.
An easy workaround is to replace snd_card_free() with
snd_card_free_when_closed(). This variant returns immediately while
the release of resources is done asynchronously by the card device
release at the last close.
This patch also splits the code to the disconnect and the free phases;
the former is called immediately at the USB disconnect callback while
the latter is called from the card destructor.