In the Linux kernel, the following vulnerability has been resolved:
ubifs: authentication: Fix use-after-free in ubifs_tnc_end_commit
After an insertion in TNC, the tree might split and cause a node to
change its `znode->parent`. A further deletion of other nodes in the
tree (which also could free the nodes), the aforementioned node's
`znode->cparent` could still point to a freed node. This
`znode->cparent` may not be updated when getting nodes to commit in
`ubifs_tnc_start_commit()`. This could then trigger a use-after-free
when accessing the `znode->cparent` in `write_index()` in
`ubifs_tnc_end_commit()`.
This can be triggered by running
rm -f /etc/test-file.bin
dd if=/dev/urandom of=/etc/test-file.bin bs=1M count=60 conv=fsync
in a loop, and with `CONFIG_UBIFS_FS_AUTHENTICATION`. KASAN then
reports:
BUG: KASAN: use-after-free in ubifs_tnc_end_commit+0xa5c/0x1950
Write of size 32 at addr ffffff800a3af86c by task ubifs_bgt0_20/153
Call trace:
dump_backtrace+0x0/0x340
show_stack+0x18/0x24
dump_stack_lvl+0x9c/0xbc
print_address_description.constprop.0+0x74/0x2b0
kasan_report+0x1d8/0x1f0
kasan_check_range+0xf8/0x1a0
memcpy+0x84/0xf4
ubifs_tnc_end_commit+0xa5c/0x1950
do_commit+0x4e0/0x1340
ubifs_bg_thread+0x234/0x2e0
kthread+0x36c/0x410
ret_from_fork+0x10/0x20
Allocated by task 401:
kasan_save_stack+0x38/0x70
__kasan_kmalloc+0x8c/0xd0
__kmalloc+0x34c/0x5bc
tnc_insert+0x140/0x16a4
ubifs_tnc_add+0x370/0x52c
ubifs_jnl_write_data+0x5d8/0x870
do_writepage+0x36c/0x510
ubifs_writepage+0x190/0x4dc
__writepage+0x58/0x154
write_cache_pages+0x394/0x830
do_writepages+0x1f0/0x5b0
filemap_fdatawrite_wbc+0x170/0x25c
file_write_and_wait_range+0x140/0x190
ubifs_fsync+0xe8/0x290
vfs_fsync_range+0xc0/0x1e4
do_fsync+0x40/0x90
__arm64_sys_fsync+0x34/0x50
invoke_syscall.constprop.0+0xa8/0x260
do_el0_svc+0xc8/0x1f0
el0_svc+0x34/0x70
el0t_64_sync_handler+0x108/0x114
el0t_64_sync+0x1a4/0x1a8
Freed by task 403:
kasan_save_stack+0x38/0x70
kasan_set_track+0x28/0x40
kasan_set_free_info+0x28/0x4c
__kasan_slab_free+0xd4/0x13c
kfree+0xc4/0x3a0
tnc_delete+0x3f4/0xe40
ubifs_tnc_remove_range+0x368/0x73c
ubifs_tnc_remove_ino+0x29c/0x2e0
ubifs_jnl_delete_inode+0x150/0x260
ubifs_evict_inode+0x1d4/0x2e4
evict+0x1c8/0x450
iput+0x2a0/0x3c4
do_unlinkat+0x2cc/0x490
__arm64_sys_unlinkat+0x90/0x100
invoke_syscall.constprop.0+0xa8/0x260
do_el0_svc+0xc8/0x1f0
el0_svc+0x34/0x70
el0t_64_sync_handler+0x108/0x114
el0t_64_sync+0x1a4/0x1a8
The offending `memcpy()` in `ubifs_copy_hash()` has a use-after-free
when a node becomes root in TNC but still has a `cparent` to an already
freed node. More specifically, consider the following TNC:
zroot
/
/
zp1
/
/
zn
Inserting a new node `zn_new` with a key smaller then `zn` will trigger
a split in `tnc_insert()` if `zp1` is full:
zroot
/ \
/ \
zp1 zp2
/ \
/ \
zn_new zn
`zn->parent` has now been moved to `zp2`, *but* `zn->cparent` still
points to `zp1`.
Now, consider a removal of all the nodes _except_ `zn`. Just when
`tnc_delete()` is about to delete `zroot` and `zp2`:
zroot
\
\
zp2
\
\
zn
`zroot` and `zp2` get freed and the tree collapses:
zn
`zn` now becomes the new `zroot`.
`get_znodes_to_commit()` will now only find `zn`, the new `zroot`, and
`write_index()` will check its `znode->cparent` that wrongly points to
the already freed `zp1`. `ubifs_copy_hash()` thus gets wrongly called
with `znode->cparent->zbranch[znode->iip].hash` that triggers the
use-after-free!
Fix this by explicitly setting `znode->cparent` to `NULL` in
`get_znodes_to_commit()` for the root node. The search for the dirty
nodes
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
ubi: fastmap: Fix duplicate slab cache names while attaching
Since commit 4c39529663b9 ("slab: Warn on duplicate cache names when
DEBUG_VM=y"), the duplicate slab cache names can be detected and a
kernel WARNING is thrown out.
In UBI fast attaching process, alloc_ai() could be invoked twice
with the same slab cache name 'ubi_aeb_slab_cache', which will trigger
following warning messages:
kmem_cache of name 'ubi_aeb_slab_cache' already exists
WARNING: CPU: 0 PID: 7519 at mm/slab_common.c:107
__kmem_cache_create_args+0x100/0x5f0
Modules linked in: ubi(+) nandsim [last unloaded: nandsim]
CPU: 0 UID: 0 PID: 7519 Comm: modprobe Tainted: G 6.12.0-rc2
RIP: 0010:__kmem_cache_create_args+0x100/0x5f0
Call Trace:
__kmem_cache_create_args+0x100/0x5f0
alloc_ai+0x295/0x3f0 [ubi]
ubi_attach+0x3c3/0xcc0 [ubi]
ubi_attach_mtd_dev+0x17cf/0x3fa0 [ubi]
ubi_init+0x3fb/0x800 [ubi]
do_init_module+0x265/0x7d0
__x64_sys_finit_module+0x7a/0xc0
The problem could be easily reproduced by loading UBI device by fastmap
with CONFIG_DEBUG_VM=y.
Fix it by using different slab names for alloc_ai() callers.
In the Linux kernel, the following vulnerability has been resolved:
NFSv4.0: Fix a use-after-free problem in the asynchronous open()
Yang Erkun reports that when two threads are opening files at the same
time, and are forced to abort before a reply is seen, then the call to
nfs_release_seqid() in nfs4_opendata_free() can result in a
use-after-free of the pointer to the defunct rpc task of the other
thread.
The fix is to ensure that if the RPC call is aborted before the call to
nfs_wait_on_sequence() is complete, then we must call nfs_release_seqid()
in nfs4_open_release() before the rpc_task is freed.
In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: make sure cache entry active before cache_show
The function `c_show` was called with protection from RCU. This only
ensures that `cp` will not be freed. Therefore, the reference count for
`cp` can drop to zero, which will trigger a refcount use-after-free
warning when `cache_get` is called. To resolve this issue, use
`cache_get_rcu` to ensure that `cp` remains active.
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 7 PID: 822 at lib/refcount.c:25
refcount_warn_saturate+0xb1/0x120
CPU: 7 UID: 0 PID: 822 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>
c_show+0x2fc/0x380 [sunrpc]
seq_read_iter+0x589/0x770
seq_read+0x1e5/0x270
proc_reg_read+0xe1/0x140
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:
sh: intc: Fix use-after-free bug in register_intc_controller()
In the error handling for this function, d is freed without ever
removing it from intc_list which would lead to a use after free.
To fix this, let's only add it to the list after everything has
succeeded.
In the Linux kernel, the following vulnerability has been resolved:
soc: qcom: geni-se: fix array underflow in geni_se_clk_tbl_get()
This loop is supposed to break if the frequency returned from
clk_round_rate() is the same as on the previous iteration. However,
that check doesn't make sense on the first iteration through the loop.
It leads to reading before the start of these->clk_perf_tbl[] array.
In the Linux kernel, the following vulnerability has been resolved:
EDAC/bluefield: Fix potential integer overflow
The 64-bit argument for the "get DIMM info" SMC call consists of mem_ctrl_idx
left-shifted 16 bits and OR-ed with DIMM index. With mem_ctrl_idx defined as
32-bits wide the left-shift operation truncates the upper 16 bits of
information during the calculation of the SMC argument.
The mem_ctrl_idx stack variable must be defined as 64-bits wide to prevent any
potential integer overflow, i.e. loss of data from upper 16 bits.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Fix out of bounds reads when finding clock sources
The current USB-audio driver code doesn't check bLength of each
descriptor at traversing for clock descriptors. That is, when a
device provides a bogus descriptor with a shorter bLength, the driver
might hit out-of-bounds reads.
For addressing it, this patch adds sanity checks to the validator
functions for the clock descriptor traversal. When the descriptor
length is shorter than expected, it's skipped in the loop.
For the clock source and clock multiplier descriptors, we can just
check bLength against the sizeof() of each descriptor type.
OTOH, the clock selector descriptor of UAC2 and UAC3 has an array
of bNrInPins elements and two more fields at its tail, hence those
have to be checked in addition to the sizeof() check.