In the Linux kernel, the following vulnerability has been resolved:
platform/x86: dell-sysman: Fix reference leak
If a duplicate attribute is found using kset_find_obj(),
a reference to that attribute is returned. This means
that we need to dispose it accordingly. Use kobject_put()
to dispose the duplicate attribute in such a case.
Compile-tested only.
In the Linux kernel, the following vulnerability has been resolved:
bpf, arm64: Fixed a BTI error on returning to patched function
When BPF_TRAMP_F_CALL_ORIG is set, BPF trampoline uses BLR to jump
back to the instruction next to call site to call the patched function.
For BTI-enabled kernel, the instruction next to call site is usually
PACIASP, in this case, it's safe to jump back with BLR. But when
the call site is not followed by a PACIASP or bti, a BTI exception
is triggered.
Here is a fault log:
Unhandled 64-bit el1h sync exception on CPU0, ESR 0x0000000034000002 -- BTI
CPU: 0 PID: 263 Comm: test_progs Tainted: GF
Hardware name: linux,dummy-virt (DT)
pstate: 40400805 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=-c)
pc : bpf_fentry_test1+0xc/0x30
lr : bpf_trampoline_6442573892_0+0x48/0x1000
sp : ffff80000c0c3a50
x29: ffff80000c0c3a90 x28: ffff0000c2e6c080 x27: 0000000000000000
x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000050
x23: 0000000000000000 x22: 0000ffffcfd2a7f0 x21: 000000000000000a
x20: 0000ffffcfd2a7f0 x19: 0000000000000000 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000ffffcfd2a7f0
x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: ffff80000914f5e4 x9 : ffff8000082a1528
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0101010101010101
x5 : 0000000000000000 x4 : 00000000fffffff2 x3 : 0000000000000001
x2 : ffff8001f4b82000 x1 : 0000000000000000 x0 : 0000000000000001
Kernel panic - not syncing: Unhandled exception
CPU: 0 PID: 263 Comm: test_progs Tainted: GF
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0xec/0x144
show_stack+0x24/0x7c
dump_stack_lvl+0x8c/0xb8
dump_stack+0x18/0x34
panic+0x1cc/0x3ec
__el0_error_handler_common+0x0/0x130
el1h_64_sync_handler+0x60/0xd0
el1h_64_sync+0x78/0x7c
bpf_fentry_test1+0xc/0x30
bpf_fentry_test1+0xc/0x30
bpf_prog_test_run_tracing+0xdc/0x2a0
__sys_bpf+0x438/0x22a0
__arm64_sys_bpf+0x30/0x54
invoke_syscall+0x78/0x110
el0_svc_common.constprop.0+0x6c/0x1d0
do_el0_svc+0x38/0xe0
el0_svc+0x30/0xd0
el0t_64_sync_handler+0x1ac/0x1b0
el0t_64_sync+0x1a0/0x1a4
Kernel Offset: disabled
CPU features: 0x0000,00034c24,f994fdab
Memory Limit: none
And the instruction next to call site of bpf_fentry_test1 is ADD,
not PACIASP:
<bpf_fentry_test1>:
bti c
nop
nop
add w0, w0, #0x1
paciasp
For BPF prog, JIT always puts a PACIASP after call site for BTI-enabled
kernel, so there is no problem. To fix it, replace BLR with RET to bypass
the branch target check.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: conntrack: fix wrong ct->timeout value
(struct nf_conn)->timeout is an interval before the conntrack
confirmed. After confirmed, it becomes a timestamp.
It is observed that timeout of an unconfirmed conntrack:
- Set by calling ctnetlink_change_timeout(). As a result,
`nfct_time_stamp` was wrongly added to `ct->timeout` twice.
- Get by calling ctnetlink_dump_timeout(). As a result,
`nfct_time_stamp` was wrongly subtracted.
Call Trace:
<TASK>
dump_stack_lvl
ctnetlink_dump_timeout
__ctnetlink_glue_build
ctnetlink_glue_build
__nfqnl_enqueue_packet
nf_queue
nf_hook_slow
ip_mc_output
? __pfx_ip_finish_output
ip_send_skb
? __pfx_dst_output
udp_send_skb
udp_sendmsg
? __pfx_ip_generic_getfrag
sock_sendmsg
Separate the 2 cases in:
- Setting `ct->timeout` in __nf_ct_set_timeout().
- Getting `ct->timeout` in ctnetlink_dump_timeout().
Pablo appends:
Update ctnetlink to set up the timeout _after_ the IPS_CONFIRMED flag is
set on, otherwise conntrack creation via ctnetlink breaks.
Note that the problem described in this patch occurs since the
introduction of the nfnetlink_queue conntrack support, select a
sufficiently old Fixes: tag for -stable kernel to pick up this fix.
In the Linux kernel, the following vulnerability has been resolved:
mm/swap: fix swap_info_struct race between swapoff and get_swap_pages()
The si->lock must be held when deleting the si from the available list.
Otherwise, another thread can re-add the si to the available list, which
can lead to memory corruption. The only place we have found where this
happens is in the swapoff path. This case can be described as below:
core 0 core 1
swapoff
del_from_avail_list(si) waiting
try lock si->lock acquire swap_avail_lock
and re-add si into
swap_avail_head
acquire si->lock but missing si already being added again, and continuing
to clear SWP_WRITEOK, etc.
It can be easily found that a massive warning messages can be triggered
inside get_swap_pages() by some special cases, for example, we call
madvise(MADV_PAGEOUT) on blocks of touched memory concurrently, meanwhile,
run much swapon-swapoff operations (e.g. stress-ng-swap).
However, in the worst case, panic can be caused by the above scene. In
swapoff(), the memory used by si could be kept in swap_info[] after
turning off a swap. This means memory corruption will not be caused
immediately until allocated and reset for a new swap in the swapon path.
A panic message caused: (with CONFIG_PLIST_DEBUG enabled)
------------[ cut here ]------------
top: 00000000e58a3003, n: 0000000013e75cda, p: 000000008cd4451a
prev: 0000000035b1e58a, n: 000000008cd4451a, p: 000000002150ee8d
next: 000000008cd4451a, n: 000000008cd4451a, p: 000000008cd4451a
WARNING: CPU: 21 PID: 1843 at lib/plist.c:60 plist_check_prev_next_node+0x50/0x70
Modules linked in: rfkill(E) crct10dif_ce(E)...
CPU: 21 PID: 1843 Comm: stress-ng Kdump: ... 5.10.134+
Hardware name: Alibaba Cloud ECS, BIOS 0.0.0 02/06/2015
pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)
pc : plist_check_prev_next_node+0x50/0x70
lr : plist_check_prev_next_node+0x50/0x70
sp : ffff0018009d3c30
x29: ffff0018009d3c40 x28: ffff800011b32a98
x27: 0000000000000000 x26: ffff001803908000
x25: ffff8000128ea088 x24: ffff800011b32a48
x23: 0000000000000028 x22: ffff001800875c00
x21: ffff800010f9e520 x20: ffff001800875c00
x19: ffff001800fdc6e0 x18: 0000000000000030
x17: 0000000000000000 x16: 0000000000000000
x15: 0736076307640766 x14: 0730073007380731
x13: 0736076307640766 x12: 0730073007380731
x11: 000000000004058d x10: 0000000085a85b76
x9 : ffff8000101436e4 x8 : ffff800011c8ce08
x7 : 0000000000000000 x6 : 0000000000000001
x5 : ffff0017df9ed338 x4 : 0000000000000001
x3 : ffff8017ce62a000 x2 : ffff0017df9ed340
x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
plist_check_prev_next_node+0x50/0x70
plist_check_head+0x80/0xf0
plist_add+0x28/0x140
add_to_avail_list+0x9c/0xf0
_enable_swap_info+0x78/0xb4
__do_sys_swapon+0x918/0xa10
__arm64_sys_swapon+0x20/0x30
el0_svc_common+0x8c/0x220
do_el0_svc+0x2c/0x90
el0_svc+0x1c/0x30
el0_sync_handler+0xa8/0xb0
el0_sync+0x148/0x180
irq event stamp: 2082270
Now, si->lock locked before calling 'del_from_avail_list()' to make sure
other thread see the si had been deleted and SWP_WRITEOK cleared together,
will not reinsert again.
This problem exists in versions after stable 5.10.y.
In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_fq: fix integer overflow of "credit"
if sch_fq is configured with "initial quantum" having values greater than
INT_MAX, the first assignment of "credit" does signed integer overflow to
a very negative value.
In this situation, the syzkaller script provided by Cristoph triggers the
CPU soft-lockup warning even with few sockets. It's not an infinite loop,
but "credit" wasn't probably meant to be minus 2Gb for each new flow.
Capping "initial quantum" to INT_MAX proved to fix the issue.
v2: validation of "initial quantum" is done in fq_policy, instead of open
coding in fq_change() _ suggested by Jakub Kicinski
In the Linux kernel, the following vulnerability has been resolved:
soc: aspeed: socinfo: Add kfree for kstrdup
Add kfree() in the later error handling in order to avoid memory leak.