In the Linux kernel, the following vulnerability has been resolved:
ftrace: Also allocate and copy hash for reading of filter files
Currently the reader of set_ftrace_filter and set_ftrace_notrace just adds
the pointer to the global tracer hash to its iterator. Unlike the writer
that allocates a copy of the hash, the reader keeps the pointer to the
filter hashes. This is problematic because this pointer is static across
function calls that release the locks that can update the global tracer
hashes. This can cause UAF and similar bugs.
Allocate and copy the hash for reading the filter files like it is done
for the writers. This not only fixes UAF bugs, but also makes the code a
bit simpler as it doesn't have to differentiate when to free the
iterator's hash between writers and readers.
In the Linux kernel, the following vulnerability has been resolved:
fs/buffer: fix use-after-free when call bh_read() helper
There's issue as follows:
BUG: KASAN: stack-out-of-bounds in end_buffer_read_sync+0xe3/0x110
Read of size 8 at addr ffffc9000168f7f8 by task swapper/3/0
CPU: 3 UID: 0 PID: 0 Comm: swapper/3 Not tainted 6.16.0-862.14.0.6.x86_64
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Call Trace:
<IRQ>
dump_stack_lvl+0x55/0x70
print_address_description.constprop.0+0x2c/0x390
print_report+0xb4/0x270
kasan_report+0xb8/0xf0
end_buffer_read_sync+0xe3/0x110
end_bio_bh_io_sync+0x56/0x80
blk_update_request+0x30a/0x720
scsi_end_request+0x51/0x2b0
scsi_io_completion+0xe3/0x480
? scsi_device_unbusy+0x11e/0x160
blk_complete_reqs+0x7b/0x90
handle_softirqs+0xef/0x370
irq_exit_rcu+0xa5/0xd0
sysvec_apic_timer_interrupt+0x6e/0x90
</IRQ>
Above issue happens when do ntfs3 filesystem mount, issue may happens
as follows:
mount IRQ
ntfs_fill_super
read_cache_page
do_read_cache_folio
filemap_read_folio
mpage_read_folio
do_mpage_readpage
ntfs_get_block_vbo
bh_read
submit_bh
wait_on_buffer(bh);
blk_complete_reqs
scsi_io_completion
scsi_end_request
blk_update_request
end_bio_bh_io_sync
end_buffer_read_sync
__end_buffer_read_notouch
unlock_buffer
wait_on_buffer(bh);--> return will return to caller
put_bh
--> trigger stack-out-of-bounds
In the mpage_read_folio() function, the stack variable 'map_bh' is
passed to ntfs_get_block_vbo(). Once unlock_buffer() unlocks and
wait_on_buffer() returns to continue processing, the stack variable
is likely to be reclaimed. Consequently, during the end_buffer_read_sync()
process, calling put_bh() may result in stack overrun.
If the bh is not allocated on the stack, it belongs to a folio. Freeing
a buffer head which belongs to a folio is done by drop_buffers() which
will fail to free buffers which are still locked. So it is safe to call
put_bh() before __end_buffer_read_notouch().
In the Linux kernel, the following vulnerability has been resolved:
net/sched: Fix backlog accounting in qdisc_dequeue_internal
This issue applies for the following qdiscs: hhf, fq, fq_codel, and
fq_pie, and occurs in their change handlers when adjusting to the new
limit. The problem is the following in the values passed to the
subsequent qdisc_tree_reduce_backlog call given a tbf parent:
When the tbf parent runs out of tokens, skbs of these qdiscs will
be placed in gso_skb. Their peek handlers are qdisc_peek_dequeued,
which accounts for both qlen and backlog. However, in the case of
qdisc_dequeue_internal, ONLY qlen is accounted for when pulling
from gso_skb. This means that these qdiscs are missing a
qdisc_qstats_backlog_dec when dropping packets to satisfy the
new limit in their change handlers.
One can observe this issue with the following (with tc patched to
support a limit of 0):
export TARGET=fq
tc qdisc del dev lo root
tc qdisc add dev lo root handle 1: tbf rate 8bit burst 100b latency 1ms
tc qdisc replace dev lo handle 3: parent 1:1 $TARGET limit 1000
echo ''; echo 'add child'; tc -s -d qdisc show dev lo
ping -I lo -f -c2 -s32 -W0.001 127.0.0.1 2>&1 >/dev/null
echo ''; echo 'after ping'; tc -s -d qdisc show dev lo
tc qdisc change dev lo handle 3: parent 1:1 $TARGET limit 0
echo ''; echo 'after limit drop'; tc -s -d qdisc show dev lo
tc qdisc replace dev lo handle 2: parent 1:1 sfq
echo ''; echo 'post graft'; tc -s -d qdisc show dev lo
The second to last show command shows 0 packets but a positive
number (74) of backlog bytes. The problem becomes clearer in the
last show command, where qdisc_purge_queue triggers
qdisc_tree_reduce_backlog with the positive backlog and causes an
underflow in the tbf parent's backlog (4096 Mb instead of 0).
To fix this issue, the codepath for all clients of qdisc_dequeue_internal
has been simplified: codel, pie, hhf, fq, fq_pie, and fq_codel.
qdisc_dequeue_internal handles the backlog adjustments for all cases that
do not directly use the dequeue handler.
The old fq_codel_change limit adjustment loop accumulated the arguments to
the subsequent qdisc_tree_reduce_backlog call through the cstats field.
However, this is confusing and error prone as fq_codel_dequeue could also
potentially mutate this field (which qdisc_dequeue_internal calls in the
non gso_skb case), so we have unified the code here with other qdiscs.
In the Linux kernel, the following vulnerability has been resolved:
tracing: Limit access to parser->buffer when trace_get_user failed
When the length of the string written to set_ftrace_filter exceeds
FTRACE_BUFF_MAX, the following KASAN alarm will be triggered:
BUG: KASAN: slab-out-of-bounds in strsep+0x18c/0x1b0
Read of size 1 at addr ffff0000d00bd5ba by task ash/165
CPU: 1 UID: 0 PID: 165 Comm: ash Not tainted 6.16.0-g6bcdbd62bd56-dirty
Hardware name: linux,dummy-virt (DT)
Call trace:
show_stack+0x34/0x50 (C)
dump_stack_lvl+0xa0/0x158
print_address_description.constprop.0+0x88/0x398
print_report+0xb0/0x280
kasan_report+0xa4/0xf0
__asan_report_load1_noabort+0x20/0x30
strsep+0x18c/0x1b0
ftrace_process_regex.isra.0+0x100/0x2d8
ftrace_regex_release+0x484/0x618
__fput+0x364/0xa58
____fput+0x28/0x40
task_work_run+0x154/0x278
do_notify_resume+0x1f0/0x220
el0_svc+0xec/0xf0
el0t_64_sync_handler+0xa0/0xe8
el0t_64_sync+0x1ac/0x1b0
The reason is that trace_get_user will fail when processing a string
longer than FTRACE_BUFF_MAX, but not set the end of parser->buffer to 0.
Then an OOB access will be triggered in ftrace_regex_release->
ftrace_process_regex->strsep->strpbrk. We can solve this problem by
limiting access to parser->buffer when trace_get_user failed.
In the Linux kernel, the following vulnerability has been resolved:
scsi: qla4xxx: Prevent a potential error pointer dereference
The qla4xxx_get_ep_fwdb() function is supposed to return NULL on error,
but qla4xxx_ep_connect() returns error pointers. Propagating the error
pointers will lead to an Oops in the caller, so change the error pointers
to NULL.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Validate UAC3 power domain descriptors, too
UAC3 power domain descriptors need to be verified with its variable
bLength for avoiding the unexpected OOB accesses by malicious
firmware, too.
In the Linux kernel, the following vulnerability has been resolved:
nfsd: handle get_client_locked() failure in nfsd4_setclientid_confirm()
Lei Lu recently reported that nfsd4_setclientid_confirm() did not check
the return value from get_client_locked(). a SETCLIENTID_CONFIRM could
race with a confirmed client expiring and fail to get a reference. That
could later lead to a UAF.
Fix this by getting a reference early in the case where there is an
extant confirmed client. If that fails then treat it as if there were no
confirmed client found at all.
In the case where the unconfirmed client is expiring, just fail and
return the result from get_client_locked().
In the Linux kernel, the following vulnerability has been resolved:
smb3: fix for slab out of bounds on mount to ksmbd
With KASAN enabled, it is possible to get a slab out of bounds
during mount to ksmbd due to missing check in parse_server_interfaces()
(see below):
BUG: KASAN: slab-out-of-bounds in
parse_server_interfaces+0x14ee/0x1880 [cifs]
Read of size 4 at addr ffff8881433dba98 by task mount/9827
CPU: 5 UID: 0 PID: 9827 Comm: mount Tainted: G
OE 6.16.0-rc2-kasan #2 PREEMPT(voluntary)
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: Dell Inc. Precision Tower 3620/0MWYPT,
BIOS 2.13.1 06/14/2019
Call Trace:
<TASK>
dump_stack_lvl+0x9f/0xf0
print_report+0xd1/0x670
__virt_addr_valid+0x22c/0x430
? parse_server_interfaces+0x14ee/0x1880 [cifs]
? kasan_complete_mode_report_info+0x2a/0x1f0
? parse_server_interfaces+0x14ee/0x1880 [cifs]
kasan_report+0xd6/0x110
parse_server_interfaces+0x14ee/0x1880 [cifs]
__asan_report_load_n_noabort+0x13/0x20
parse_server_interfaces+0x14ee/0x1880 [cifs]
? __pfx_parse_server_interfaces+0x10/0x10 [cifs]
? trace_hardirqs_on+0x51/0x60
SMB3_request_interfaces+0x1ad/0x3f0 [cifs]
? __pfx_SMB3_request_interfaces+0x10/0x10 [cifs]
? SMB2_tcon+0x23c/0x15d0 [cifs]
smb3_qfs_tcon+0x173/0x2b0 [cifs]
? __pfx_smb3_qfs_tcon+0x10/0x10 [cifs]
? cifs_get_tcon+0x105d/0x2120 [cifs]
? do_raw_spin_unlock+0x5d/0x200
? cifs_get_tcon+0x105d/0x2120 [cifs]
? __pfx_smb3_qfs_tcon+0x10/0x10 [cifs]
cifs_mount_get_tcon+0x369/0xb90 [cifs]
? dfs_cache_find+0xe7/0x150 [cifs]
dfs_mount_share+0x985/0x2970 [cifs]
? check_path.constprop.0+0x28/0x50
? save_trace+0x54/0x370
? __pfx_dfs_mount_share+0x10/0x10 [cifs]
? __lock_acquire+0xb82/0x2ba0
? __kasan_check_write+0x18/0x20
cifs_mount+0xbc/0x9e0 [cifs]
? __pfx_cifs_mount+0x10/0x10 [cifs]
? do_raw_spin_unlock+0x5d/0x200
? cifs_setup_cifs_sb+0x29d/0x810 [cifs]
cifs_smb3_do_mount+0x263/0x1990 [cifs]