In the Linux kernel, the following vulnerability has been resolved:
orangefs: Fix kmemleak in orangefs_{kernel,client}_debug_init()
When insert and remove the orangefs module, there are memory leaked
as below:
unreferenced object 0xffff88816b0cc000 (size 2048):
comm "insmod", pid 783, jiffies 4294813439 (age 65.512s)
hex dump (first 32 bytes):
6e 6f 6e 65 0a 00 00 00 00 00 00 00 00 00 00 00 none............
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000031ab7788>] kmalloc_trace+0x27/0xa0
[<000000005b405fee>] orangefs_debugfs_init.cold+0xaf/0x17f
[<00000000e5a0085b>] 0xffffffffa02780f9
[<000000004232d9f7>] do_one_initcall+0x87/0x2a0
[<0000000054f22384>] do_init_module+0xdf/0x320
[<000000003263bdea>] load_module+0x2f98/0x3330
[<0000000052cd4153>] __do_sys_finit_module+0x113/0x1b0
[<00000000250ae02b>] do_syscall_64+0x35/0x80
[<00000000f11c03c7>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
Use the golbal variable as the buffer rather than dynamic allocate to
slove the problem.
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix race between quota enable and quota rescan ioctl
When enabling quotas, at btrfs_quota_enable(), after committing the
transaction, we change fs_info->quota_root to point to the quota root we
created and set BTRFS_FS_QUOTA_ENABLED at fs_info->flags. Then we try
to start the qgroup rescan worker, first by initializing it with a call
to qgroup_rescan_init() - however if that fails we end up freeing the
quota root but we leave fs_info->quota_root still pointing to it, this
can later result in a use-after-free somewhere else.
We have previously set the flags BTRFS_FS_QUOTA_ENABLED and
BTRFS_QGROUP_STATUS_FLAG_ON, so we can only fail with -EINPROGRESS at
btrfs_quota_enable(), which is possible if someone already called the
quota rescan ioctl, and therefore started the rescan worker.
So fix this by ignoring an -EINPROGRESS and asserting we can't get any
other error.
In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix race issue between cpu buffer write and swap
Warning happened in rb_end_commit() at code:
if (RB_WARN_ON(cpu_buffer, !local_read(&cpu_buffer->committing)))
WARNING: CPU: 0 PID: 139 at kernel/trace/ring_buffer.c:3142
rb_commit+0x402/0x4a0
Call Trace:
ring_buffer_unlock_commit+0x42/0x250
trace_buffer_unlock_commit_regs+0x3b/0x250
trace_event_buffer_commit+0xe5/0x440
trace_event_buffer_reserve+0x11c/0x150
trace_event_raw_event_sched_switch+0x23c/0x2c0
__traceiter_sched_switch+0x59/0x80
__schedule+0x72b/0x1580
schedule+0x92/0x120
worker_thread+0xa0/0x6f0
It is because the race between writing event into cpu buffer and swapping
cpu buffer through file per_cpu/cpu0/snapshot:
Write on CPU 0 Swap buffer by per_cpu/cpu0/snapshot on CPU 1
-------- --------
tracing_snapshot_write()
[...]
ring_buffer_lock_reserve()
cpu_buffer = buffer->buffers[cpu]; // 1. Suppose find 'cpu_buffer_a';
[...]
rb_reserve_next_event()
[...]
ring_buffer_swap_cpu()
if (local_read(&cpu_buffer_a->committing))
goto out_dec;
if (local_read(&cpu_buffer_b->committing))
goto out_dec;
buffer_a->buffers[cpu] = cpu_buffer_b;
buffer_b->buffers[cpu] = cpu_buffer_a;
// 2. cpu_buffer has swapped here.
rb_start_commit(cpu_buffer);
if (unlikely(READ_ONCE(cpu_buffer->buffer)
!= buffer)) { // 3. This check passed due to 'cpu_buffer->buffer'
[...] // has not changed here.
return NULL;
}
cpu_buffer_b->buffer = buffer_a;
cpu_buffer_a->buffer = buffer_b;
[...]
// 4. Reserve event from 'cpu_buffer_a'.
ring_buffer_unlock_commit()
[...]
cpu_buffer = buffer->buffers[cpu]; // 5. Now find 'cpu_buffer_b' !!!
rb_commit(cpu_buffer)
rb_end_commit() // 6. WARN for the wrong 'committing' state !!!
Based on above analysis, we can easily reproduce by following testcase:
``` bash
#!/bin/bash
dmesg -n 7
sysctl -w kernel.panic_on_warn=1
TR=/sys/kernel/tracing
echo 7 > ${TR}/buffer_size_kb
echo "sched:sched_switch" > ${TR}/set_event
while [ true ]; do
echo 1 > ${TR}/per_cpu/cpu0/snapshot
done &
while [ true ]; do
echo 1 > ${TR}/per_cpu/cpu0/snapshot
done &
while [ true ]; do
echo 1 > ${TR}/per_cpu/cpu0/snapshot
done &
```
To fix it, IIUC, we can use smp_call_function_single() to do the swap on
the target cpu where the buffer is located, so that above race would be
avoided.
In the Linux kernel, the following vulnerability has been resolved:
USB: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic at
once.
In the Linux kernel, the following vulnerability has been resolved:
staging: pi433: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once. This requires saving off the root directory dentry to make
creation of individual device subdirectories easier.
In the Linux kernel, the following vulnerability has been resolved:
md/raid10: check slab-out-of-bounds in md_bitmap_get_counter
If we write a large number to md/bitmap_set_bits, md_bitmap_checkpage()
will return -EINVAL because 'page >= bitmap->pages', but the return value
was not checked immediately in md_bitmap_get_counter() in order to set
*blocks value and slab-out-of-bounds occurs.
Move check of 'page >= bitmap->pages' to md_bitmap_get_counter() and
return directly if true.
In the Linux kernel, the following vulnerability has been resolved:
icmp6: Fix null-ptr-deref of ip6_null_entry->rt6i_idev in icmp6_dev().
With some IPv6 Ext Hdr (RPL, SRv6, etc.), we can send a packet that
has the link-local address as src and dst IP and will be forwarded to
an external IP in the IPv6 Ext Hdr.
For example, the script below generates a packet whose src IP is the
link-local address and dst is updated to 11::.
# for f in $(find /proc/sys/net/ -name *seg6_enabled*); do echo 1 > $f; done
# python3
>>> from socket import *
>>> from scapy.all import *
>>>
>>> SRC_ADDR = DST_ADDR = "fe80::5054:ff:fe12:3456"
>>>
>>> pkt = IPv6(src=SRC_ADDR, dst=DST_ADDR)
>>> pkt /= IPv6ExtHdrSegmentRouting(type=4, addresses=["11::", "22::"], segleft=1)
>>>
>>> sk = socket(AF_INET6, SOCK_RAW, IPPROTO_RAW)
>>> sk.sendto(bytes(pkt), (DST_ADDR, 0))
For such a packet, we call ip6_route_input() to look up a route for the
next destination in these three functions depending on the header type.
* ipv6_rthdr_rcv()
* ipv6_rpl_srh_rcv()
* ipv6_srh_rcv()
If no route is found, ip6_null_entry is set to skb, and the following
dst_input(skb) calls ip6_pkt_drop().
Finally, in icmp6_dev(), we dereference skb_rt6_info(skb)->rt6i_idev->dev
as the input device is the loopback interface. Then, we have to check if
skb_rt6_info(skb)->rt6i_idev is NULL or not to avoid NULL pointer deref
for ip6_null_entry.
BUG: kernel NULL pointer dereference, address: 0000000000000000
PF: supervisor read access in kernel mode
PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 157 Comm: python3 Not tainted 6.4.0-11996-gb121d614371c #35
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:icmp6_send (net/ipv6/icmp.c:436 net/ipv6/icmp.c:503)
Code: fe ff ff 48 c7 40 30 c0 86 5d 83 e8 c6 44 1c 00 e9 c8 fc ff ff 49 8b 46 58 48 83 e0 fe 0f 84 4a fb ff ff 48 8b 80 d0 00 00 00 <48> 8b 00 44 8b 88 e0 00 00 00 e9 34 fb ff ff 4d 85 ed 0f 85 69 01
RSP: 0018:ffffc90000003c70 EFLAGS: 00000286
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 00000000000000e0
RDX: 0000000000000021 RSI: 0000000000000000 RDI: ffff888006d72a18
RBP: ffffc90000003d80 R08: 0000000000000000 R09: 0000000000000001
R10: ffffc90000003d98 R11: 0000000000000040 R12: ffff888006d72a10
R13: 0000000000000000 R14: ffff8880057fb800 R15: ffffffff835d86c0
FS: 00007f9dc72ee740(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000057b2000 CR4: 00000000007506f0
PKRU: 55555554
Call Trace:
<IRQ>
ip6_pkt_drop (net/ipv6/route.c:4513)
ipv6_rthdr_rcv (net/ipv6/exthdrs.c:640 net/ipv6/exthdrs.c:686)
ip6_protocol_deliver_rcu (net/ipv6/ip6_input.c:437 (discriminator 5))
ip6_input_finish (./include/linux/rcupdate.h:781 net/ipv6/ip6_input.c:483)
__netif_receive_skb_one_core (net/core/dev.c:5455)
process_backlog (./include/linux/rcupdate.h:781 net/core/dev.c:5895)
__napi_poll (net/core/dev.c:6460)
net_rx_action (net/core/dev.c:6529 net/core/dev.c:6660)
__do_softirq (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/irq.h:142 kernel/softirq.c:554)
do_softirq (kernel/softirq.c:454 kernel/softirq.c:441)
</IRQ>
<TASK>
__local_bh_enable_ip (kernel/softirq.c:381)
__dev_queue_xmit (net/core/dev.c:4231)
ip6_finish_output2 (./include/net/neighbour.h:544 net/ipv6/ip6_output.c:135)
rawv6_sendmsg (./include/net/dst.h:458 ./include/linux/netfilter.h:303 net/ipv6/raw.c:656 net/ipv6/raw.c:914)
sock_sendmsg (net/socket.c:725 net/socket.c:748)
__sys_sendto (net/socket.c:2134)
__x64_sys_sendto (net/socket.c:2146 net/socket.c:2142 net/socket.c:2142)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
RIP: 0033:0x7f9dc751baea
Code: d8 64 89 02 48 c7 c0 ff f
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
kernel/fail_function: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.