In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conncount: update last_gc only when GC has been performed
Currently last_gc is being updated everytime a new connection is
tracked, that means that it is updated even if a GC wasn't performed.
With a sufficiently high packet rate, it is possible to always bypass
the GC, causing the list to grow infinitely.
Update the last_gc value only when a GC has been actually performed.
In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix early read unlock of page with EOF in middle
The read result collection for buffered reads seems to run ahead of the
completion of subrequests under some circumstances, as can be seen in the
following log snippet:
9p_client_res: client 18446612686390831168 response P9_TREAD tag 0 err 0
...
netfs_sreq: R=00001b55[1] DOWN TERM f=192 s=0 5fb2/5fb2 s=5 e=0
...
netfs_collect_folio: R=00001b55 ix=00004 r=4000-5000 t=4000/5fb2
netfs_folio: i=157f3 ix=00004-00004 read-done
netfs_folio: i=157f3 ix=00004-00004 read-unlock
netfs_collect_folio: R=00001b55 ix=00005 r=5000-5fb2 t=5000/5fb2
netfs_folio: i=157f3 ix=00005-00005 read-done
netfs_folio: i=157f3 ix=00005-00005 read-unlock
...
netfs_collect_stream: R=00001b55[0:] cto=5fb2 frn=ffffffff
netfs_collect_state: R=00001b55 col=5fb2 cln=6000 n=c
netfs_collect_stream: R=00001b55[0:] cto=5fb2 frn=ffffffff
netfs_collect_state: R=00001b55 col=5fb2 cln=6000 n=8
...
netfs_sreq: R=00001b55[2] ZERO SUBMT f=000 s=5fb2 0/4e s=0 e=0
netfs_sreq: R=00001b55[2] ZERO TERM f=102 s=5fb2 4e/4e s=5 e=0
The 'cto=5fb2' indicates the collected file pos we've collected results to
so far - but we still have 0x4e more bytes to go - so we shouldn't have
collected folio ix=00005 yet. The 'ZERO' subreq that clears the tail
happens after we unlock the folio, allowing the application to see the
uncleared tail through mmap.
The problem is that netfs_read_unlock_folios() will unlock a folio in which
the amount of read results collected hits EOF position - but the ZERO
subreq lies beyond that and so happens after.
Fix this by changing the end check to always be the end of the folio and
never the end of the file.
In the future, I should look at clearing to the end of the folio here rather
than adding a ZERO subreq to do this. On the other hand, the ZERO subreq can
run in parallel with an async READ subreq. Further, the ZERO subreq may still
be necessary to, say, handle extents in a ceph file that don't have any
backing store and are thus implicitly all zeros.
This can be reproduced by creating a file, the size of which doesn't align
to a page boundary, e.g. 24998 (0x5fb2) bytes and then doing something
like:
xfs_io -c "mmap -r 0 0x6000" -c "madvise -d 0 0x6000" \
-c "mread -v 0 0x6000" /xfstest.test/x
The last 0x4e bytes should all be 00, but if the tail hasn't been cleared
yet, you may see rubbish there. This can be reproduced with kafs by
modifying the kernel to disable the call to netfs_read_subreq_progress()
and to stop afs_issue_read() from doing the async call for NETFS_READAHEAD.
Reproduction can be made easier by inserting an mdelay(100) in
netfs_issue_read() for the ZERO-subreq case.
AFS and CIFS are normally unlikely to show this as they dispatch READ ops
asynchronously, which allows the ZERO-subreq to finish first. 9P's READ op is
completely synchronous, so the ZERO-subreq will always happen after. It isn't
seen all the time, though, because the collection may be done in a worker
thread.
In the Linux kernel, the following vulnerability has been resolved:
iommu/sva: invalidate stale IOTLB entries for kernel address space
Introduce a new IOMMU interface to flush IOTLB paging cache entries for
the CPU kernel address space. This interface is invoked from the x86
architecture code that manages combined user and kernel page tables,
specifically before any kernel page table page is freed and reused.
This addresses the main issue with vfree() which is a common occurrence
and can be triggered by unprivileged users. While this resolves the
primary problem, it doesn't address some extremely rare case related to
memory unplug of memory that was present as reserved memory at boot, which
cannot be triggered by unprivileged users. The discussion can be found at
the link below.
Enable SVA on x86 architecture since the IOMMU can now receive
notification to flush the paging cache before freeing the CPU kernel page
table pages.
In the Linux kernel, the following vulnerability has been resolved:
dpll: Prevent duplicate registrations
Modify the internal registration helpers dpll_xa_ref_{dpll,pin}_add()
to reject duplicate registration attempts.
Previously, if a caller attempted to register the same pin multiple
times (with the same ops, priv, and cookie) on the same device, the core
silently increments the reference count and return success. This behavior
is incorrect because if the caller makes these duplicate registrations
then for the first one dpll_pin_registration is allocated and for others
the associated dpll_pin_ref.refcount is incremented. During the first
unregistration the associated dpll_pin_registration is freed and for
others WARN is fired.
Fix this by updating the logic to return `-EEXIST` if a matching
registration is found to enforce a strict "register once" policy.
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath12k: fix dead lock while flushing management frames
Commit [1] converted the management transmission work item into a
wiphy work. Since a wiphy work can only run under wiphy lock
protection, a race condition happens in below scenario:
1. a management frame is queued for transmission.
2. ath12k_mac_op_flush() gets called to flush pending frames associated
with the hardware (i.e, vif being NULL). Then in ath12k_mac_flush()
the process waits for the transmission done.
3. Since wiphy lock has been taken by the flush process, the transmission
work item has no chance to run, hence the dead lock.
>From user view, this dead lock results in below issue:
wlp8s0: authenticate with xxxxxx (local address=xxxxxx)
wlp8s0: send auth to xxxxxx (try 1/3)
wlp8s0: authenticate with xxxxxx (local address=xxxxxx)
wlp8s0: send auth to xxxxxx (try 1/3)
wlp8s0: authenticated
wlp8s0: associate with xxxxxx (try 1/3)
wlp8s0: aborting association with xxxxxx by local choice (Reason: 3=DEAUTH_LEAVING)
ath12k_pci 0000:08:00.0: failed to flush mgmt transmit queue, mgmt pkts pending 1
The dead lock can be avoided by invoking wiphy_work_flush() to proactively
run the queued work item. Note actually it is already present in
ath12k_mac_op_flush(), however it does not protect the case where vif
being NULL. Hence move it ahead to cover this case as well.
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00302-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.115823.3
In the Linux kernel, the following vulnerability has been resolved:
platform/x86: hp-bioscfg: Fix kobject warnings for empty attribute names
The hp-bioscfg driver attempts to register kobjects with empty names when
the HP BIOS returns attributes with empty name strings. This causes
multiple kernel warnings:
kobject: (00000000135fb5e6): attempted to be registered with empty name!
WARNING: CPU: 14 PID: 3336 at lib/kobject.c:219 kobject_add_internal+0x2eb/0x310
Add validation in hp_init_bios_buffer_attribute() to check if the
attribute name is empty after parsing it from the WMI buffer. If empty,
log a debug message and skip registration of that attribute, allowing the
module to continue processing other valid attributes.
In the Linux kernel, the following vulnerability has been resolved:
bonding: provide a net pointer to __skb_flow_dissect()
After 3cbf4ffba5ee ("net: plumb network namespace into __skb_flow_dissect")
we have to provide a net pointer to __skb_flow_dissect(),
either via skb->dev, skb->sk, or a user provided pointer.
In the following case, syzbot was able to cook a bare skb.
WARNING: net/core/flow_dissector.c:1131 at __skb_flow_dissect+0xb57/0x68b0 net/core/flow_dissector.c:1131, CPU#1: syz.2.1418/11053
Call Trace:
<TASK>
bond_flow_dissect drivers/net/bonding/bond_main.c:4093 [inline]
__bond_xmit_hash+0x2d7/0xba0 drivers/net/bonding/bond_main.c:4157
bond_xmit_hash_xdp drivers/net/bonding/bond_main.c:4208 [inline]
bond_xdp_xmit_3ad_xor_slave_get drivers/net/bonding/bond_main.c:5139 [inline]
bond_xdp_get_xmit_slave+0x1fd/0x710 drivers/net/bonding/bond_main.c:5515
xdp_master_redirect+0x13f/0x2c0 net/core/filter.c:4388
bpf_prog_run_xdp include/net/xdp.h:700 [inline]
bpf_test_run+0x6b2/0x7d0 net/bpf/test_run.c:421
bpf_prog_test_run_xdp+0x795/0x10e0 net/bpf/test_run.c:1390
bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4703
__sys_bpf+0x562/0x860 kernel/bpf/syscall.c:6182
__do_sys_bpf kernel/bpf/syscall.c:6274 [inline]
__se_sys_bpf kernel/bpf/syscall.c:6272 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6272
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
In the Linux kernel, the following vulnerability has been resolved:
l2tp: avoid one data-race in l2tp_tunnel_del_work()
We should read sk->sk_socket only when dealing with kernel sockets.
syzbot reported the following data-race:
BUG: KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release
write to 0xffff88811c182b20 of 8 bytes by task 5365 on cpu 0:
sk_set_socket include/net/sock.h:2092 [inline]
sock_orphan include/net/sock.h:2118 [inline]
sk_common_release+0xae/0x230 net/core/sock.c:4003
udp_lib_close+0x15/0x20 include/net/udp.h:325
inet_release+0xce/0xf0 net/ipv4/af_inet.c:437
__sock_release net/socket.c:662 [inline]
sock_close+0x6b/0x150 net/socket.c:1455
__fput+0x29b/0x650 fs/file_table.c:468
____fput+0x1c/0x30 fs/file_table.c:496
task_work_run+0x131/0x1a0 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0x1fe/0x740 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x1e1/0x2b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
read to 0xffff88811c182b20 of 8 bytes by task 827 on cpu 1:
l2tp_tunnel_del_work+0x2f/0x1a0 net/l2tp/l2tp_core.c:1418
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3340
worker_thread+0x582/0x770 kernel/workqueue.c:3421
kthread+0x489/0x510 kernel/kthread.c:463
ret_from_fork+0x149/0x290 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
value changed: 0xffff88811b818000 -> 0x0000000000000000
In the Linux kernel, the following vulnerability has been resolved:
mISDN: annotate data-race around dev->work
dev->work can re read locklessly in mISDN_read()
and mISDN_poll(). Add READ_ONCE()/WRITE_ONCE() annotations.
BUG: KCSAN: data-race in mISDN_ioctl / mISDN_read
write to 0xffff88812d848280 of 4 bytes by task 10864 on cpu 1:
misdn_add_timer drivers/isdn/mISDN/timerdev.c:175 [inline]
mISDN_ioctl+0x2fb/0x550 drivers/isdn/mISDN/timerdev.c:233
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xce/0x140 fs/ioctl.c:583
__x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583
x64_sys_call+0x14b0/0x3000 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
read to 0xffff88812d848280 of 4 bytes by task 10857 on cpu 0:
mISDN_read+0x1f2/0x470 drivers/isdn/mISDN/timerdev.c:112
do_loop_readv_writev fs/read_write.c:847 [inline]
vfs_readv+0x3fb/0x690 fs/read_write.c:1020
do_readv+0xe7/0x210 fs/read_write.c:1080
__do_sys_readv fs/read_write.c:1165 [inline]
__se_sys_readv fs/read_write.c:1162 [inline]
__x64_sys_readv+0x45/0x50 fs/read_write.c:1162
x64_sys_call+0x2831/0x3000 arch/x86/include/generated/asm/syscalls_64.h:20
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
value changed: 0x00000000 -> 0x00000001