In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmfmac: Check the count value of channel spec to prevent out-of-bounds reads
This patch fixes slab-out-of-bounds reads in brcmfmac that occur in
brcmf_construct_chaninfo() and brcmf_enable_bw40_2g() when the count
value of channel specifications provided by the device is greater than
the length of 'list->element[]', decided by the size of the 'list'
allocated with kzalloc(). The patch adds checks that make the functions
free the buffer and return -EINVAL if that is the case. Note that the
negative return is handled by the caller, brcmf_setup_wiphybands() or
brcmf_cfg80211_attach().
Found by a modified version of syzkaller.
Crash Report from brcmf_construct_chaninfo():
==================================================================
BUG: KASAN: slab-out-of-bounds in brcmf_setup_wiphybands+0x1238/0x1430
Read of size 4 at addr ffff888115f24600 by task kworker/0:2/1896
CPU: 0 PID: 1896 Comm: kworker/0:2 Tainted: G W O 5.14.0+ #132
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
Workqueue: usb_hub_wq hub_event
Call Trace:
dump_stack_lvl+0x57/0x7d
print_address_description.constprop.0.cold+0x93/0x334
kasan_report.cold+0x83/0xdf
brcmf_setup_wiphybands+0x1238/0x1430
brcmf_cfg80211_attach+0x2118/0x3fd0
brcmf_attach+0x389/0xd40
brcmf_usb_probe+0x12de/0x1690
usb_probe_interface+0x25f/0x710
really_probe+0x1be/0xa90
__driver_probe_device+0x2ab/0x460
driver_probe_device+0x49/0x120
__device_attach_driver+0x18a/0x250
bus_for_each_drv+0x123/0x1a0
__device_attach+0x207/0x330
bus_probe_device+0x1a2/0x260
device_add+0xa61/0x1ce0
usb_set_configuration+0x984/0x1770
usb_generic_driver_probe+0x69/0x90
usb_probe_device+0x9c/0x220
really_probe+0x1be/0xa90
__driver_probe_device+0x2ab/0x460
driver_probe_device+0x49/0x120
__device_attach_driver+0x18a/0x250
bus_for_each_drv+0x123/0x1a0
__device_attach+0x207/0x330
bus_probe_device+0x1a2/0x260
device_add+0xa61/0x1ce0
usb_new_device.cold+0x463/0xf66
hub_event+0x10d5/0x3330
process_one_work+0x873/0x13e0
worker_thread+0x8b/0xd10
kthread+0x379/0x450
ret_from_fork+0x1f/0x30
Allocated by task 1896:
kasan_save_stack+0x1b/0x40
__kasan_kmalloc+0x7c/0x90
kmem_cache_alloc_trace+0x19e/0x330
brcmf_setup_wiphybands+0x290/0x1430
brcmf_cfg80211_attach+0x2118/0x3fd0
brcmf_attach+0x389/0xd40
brcmf_usb_probe+0x12de/0x1690
usb_probe_interface+0x25f/0x710
really_probe+0x1be/0xa90
__driver_probe_device+0x2ab/0x460
driver_probe_device+0x49/0x120
__device_attach_driver+0x18a/0x250
bus_for_each_drv+0x123/0x1a0
__device_attach+0x207/0x330
bus_probe_device+0x1a2/0x260
device_add+0xa61/0x1ce0
usb_set_configuration+0x984/0x1770
usb_generic_driver_probe+0x69/0x90
usb_probe_device+0x9c/0x220
really_probe+0x1be/0xa90
__driver_probe_device+0x2ab/0x460
driver_probe_device+0x49/0x120
__device_attach_driver+0x18a/0x250
bus_for_each_drv+0x123/0x1a0
__device_attach+0x207/0x330
bus_probe_device+0x1a2/0x260
device_add+0xa61/0x1ce0
usb_new_device.cold+0x463/0xf66
hub_event+0x10d5/0x3330
process_one_work+0x873/0x13e0
worker_thread+0x8b/0xd10
kthread+0x379/0x450
ret_from_fork+0x1f/0x30
The buggy address belongs to the object at ffff888115f24000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1536 bytes inside of
2048-byte region [ffff888115f24000, ffff888115f24800)
Memory state around the buggy address:
ffff888115f24500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888115f24580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888115f24600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff888115f24680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888115f24700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
Crash Report from brcmf_enable_bw40_2g():
==========
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
f2fs: initialize locks earlier in f2fs_fill_super()
syzbot is reporting lockdep warning at f2fs_handle_error() [1], for
spin_lock(&sbi->error_lock) is called before spin_lock_init() is called.
For safe locking in error handling, move initialization of locks (and
obvious structures) in f2fs_fill_super() to immediately after memory
allocation.
In the Linux kernel, the following vulnerability has been resolved:
ovl: Use "buf" flexible array for memcpy() destination
The "buf" flexible array needs to be the memcpy() destination to avoid
false positive run-time warning from the recent FORTIFY_SOURCE
hardening:
memcpy: detected field-spanning write (size 93) of single field "&fh->fb"
at fs/overlayfs/export.c:799 (size 21)
In the Linux kernel, the following vulnerability has been resolved:
uprobes: Reject the shared zeropage in uprobe_write_opcode()
We triggered the following crash in syzkaller tests:
BUG: Bad page state in process syz.7.38 pfn:1eff3
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1eff3
flags: 0x3fffff00004004(referenced|reserved|node=0|zone=1|lastcpupid=0x1fffff)
raw: 003fffff00004004 ffffe6c6c07bfcc8 ffffe6c6c07bfcc8 0000000000000000
raw: 0000000000000000 0000000000000000 00000000fffffffe 0000000000000000
page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x32/0x50
bad_page+0x69/0xf0
free_unref_page_prepare+0x401/0x500
free_unref_page+0x6d/0x1b0
uprobe_write_opcode+0x460/0x8e0
install_breakpoint.part.0+0x51/0x80
register_for_each_vma+0x1d9/0x2b0
__uprobe_register+0x245/0x300
bpf_uprobe_multi_link_attach+0x29b/0x4f0
link_create+0x1e2/0x280
__sys_bpf+0x75f/0xac0
__x64_sys_bpf+0x1a/0x30
do_syscall_64+0x56/0x100
entry_SYSCALL_64_after_hwframe+0x78/0xe2
BUG: Bad rss-counter state mm:00000000452453e0 type:MM_FILEPAGES val:-1
The following syzkaller test case can be used to reproduce:
r2 = creat(&(0x7f0000000000)='./file0\x00', 0x8)
write$nbd(r2, &(0x7f0000000580)=ANY=[], 0x10)
r4 = openat(0xffffffffffffff9c, &(0x7f0000000040)='./file0\x00', 0x42, 0x0)
mmap$IORING_OFF_SQ_RING(&(0x7f0000ffd000/0x3000)=nil, 0x3000, 0x0, 0x12, r4, 0x0)
r5 = userfaultfd(0x80801)
ioctl$UFFDIO_API(r5, 0xc018aa3f, &(0x7f0000000040)={0xaa, 0x20})
r6 = userfaultfd(0x80801)
ioctl$UFFDIO_API(r6, 0xc018aa3f, &(0x7f0000000140))
ioctl$UFFDIO_REGISTER(r6, 0xc020aa00, &(0x7f0000000100)={{&(0x7f0000ffc000/0x4000)=nil, 0x4000}, 0x2})
ioctl$UFFDIO_ZEROPAGE(r5, 0xc020aa04, &(0x7f0000000000)={{&(0x7f0000ffd000/0x1000)=nil, 0x1000}})
r7 = bpf$PROG_LOAD(0x5, &(0x7f0000000140)={0x2, 0x3, &(0x7f0000000200)=ANY=[@ANYBLOB="1800000000120000000000000000000095"], &(0x7f0000000000)='GPL\x00', 0x7, 0x0, 0x0, 0x0, 0x0, '\x00', 0x0, @fallback=0x30, 0xffffffffffffffff, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x10, 0x0, @void, @value}, 0x94)
bpf$BPF_LINK_CREATE_XDP(0x1c, &(0x7f0000000040)={r7, 0x0, 0x30, 0x1e, @val=@uprobe_multi={&(0x7f0000000080)='./file0\x00', &(0x7f0000000100)=[0x2], 0x0, 0x0, 0x1}}, 0x40)
The cause is that zero pfn is set to the PTE without increasing the RSS
count in mfill_atomic_pte_zeropage() and the refcount of zero folio does
not increase accordingly. Then, the operation on the same pfn is performed
in uprobe_write_opcode()->__replace_page() to unconditional decrease the
RSS count and old_folio's refcount.
Therefore, two bugs are introduced:
1. The RSS count is incorrect, when process exit, the check_mm() report
error "Bad rss-count".
2. The reserved folio (zero folio) is freed when folio->refcount is zero,
then free_pages_prepare->free_page_is_bad() report error
"Bad page state".
There is more, the following warning could also theoretically be triggered:
__replace_page()
-> ...
-> folio_remove_rmap_pte()
-> VM_WARN_ON_FOLIO(is_zero_folio(folio), folio)
Considering that uprobe hit on the zero folio is a very rare case, just
reject zero old folio immediately after get_user_page_vma_remote().
[ mingo: Cleaned up the changelog ]
In the Linux kernel, the following vulnerability has been resolved:
usbnet: gl620a: fix endpoint checking in genelink_bind()
Syzbot reports [1] a warning in usb_submit_urb() triggered by
inconsistencies between expected and actually present endpoints
in gl620a driver. Since genelink_bind() does not properly
verify whether specified eps are in fact provided by the device,
in this case, an artificially manufactured one, one may get a
mismatch.
Fix the issue by resorting to a usbnet utility function
usbnet_get_endpoints(), usually reserved for this very problem.
Check for endpoints and return early before proceeding further if
any are missing.
[1] Syzbot report:
usb 5-1: Manufacturer: syz
usb 5-1: SerialNumber: syz
usb 5-1: config 0 descriptor??
gl620a 5-1:0.23 usb0: register 'gl620a' at usb-dummy_hcd.0-1, ...
------------[ cut here ]------------
usb 5-1: BOGUS urb xfer, pipe 3 != type 1
WARNING: CPU: 2 PID: 1841 at drivers/usb/core/urb.c:503 usb_submit_urb+0xe4b/0x1730 drivers/usb/core/urb.c:503
Modules linked in:
CPU: 2 UID: 0 PID: 1841 Comm: kworker/2:2 Not tainted 6.12.0-syzkaller-07834-g06afb0f36106 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: mld mld_ifc_work
RIP: 0010:usb_submit_urb+0xe4b/0x1730 drivers/usb/core/urb.c:503
...
Call Trace:
<TASK>
usbnet_start_xmit+0x6be/0x2780 drivers/net/usb/usbnet.c:1467
__netdev_start_xmit include/linux/netdevice.h:5002 [inline]
netdev_start_xmit include/linux/netdevice.h:5011 [inline]
xmit_one net/core/dev.c:3590 [inline]
dev_hard_start_xmit+0x9a/0x7b0 net/core/dev.c:3606
sch_direct_xmit+0x1ae/0xc30 net/sched/sch_generic.c:343
__dev_xmit_skb net/core/dev.c:3827 [inline]
__dev_queue_xmit+0x13d4/0x43e0 net/core/dev.c:4400
dev_queue_xmit include/linux/netdevice.h:3168 [inline]
neigh_resolve_output net/core/neighbour.c:1514 [inline]
neigh_resolve_output+0x5bc/0x950 net/core/neighbour.c:1494
neigh_output include/net/neighbour.h:539 [inline]
ip6_finish_output2+0xb1b/0x2070 net/ipv6/ip6_output.c:141
__ip6_finish_output net/ipv6/ip6_output.c:215 [inline]
ip6_finish_output+0x3f9/0x1360 net/ipv6/ip6_output.c:226
NF_HOOK_COND include/linux/netfilter.h:303 [inline]
ip6_output+0x1f8/0x540 net/ipv6/ip6_output.c:247
dst_output include/net/dst.h:450 [inline]
NF_HOOK include/linux/netfilter.h:314 [inline]
NF_HOOK include/linux/netfilter.h:308 [inline]
mld_sendpack+0x9f0/0x11d0 net/ipv6/mcast.c:1819
mld_send_cr net/ipv6/mcast.c:2120 [inline]
mld_ifc_work+0x740/0xca0 net/ipv6/mcast.c:2651
process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
In the Linux kernel, the following vulnerability has been resolved:
sched/core: Prevent rescheduling when interrupts are disabled
David reported a warning observed while loop testing kexec jump:
Interrupts enabled after irqrouter_resume+0x0/0x50
WARNING: CPU: 0 PID: 560 at drivers/base/syscore.c:103 syscore_resume+0x18a/0x220
kernel_kexec+0xf6/0x180
__do_sys_reboot+0x206/0x250
do_syscall_64+0x95/0x180
The corresponding interrupt flag trace:
hardirqs last enabled at (15573): [<ffffffffa8281b8e>] __up_console_sem+0x7e/0x90
hardirqs last disabled at (15580): [<ffffffffa8281b73>] __up_console_sem+0x63/0x90
That means __up_console_sem() was invoked with interrupts enabled. Further
instrumentation revealed that in the interrupt disabled section of kexec
jump one of the syscore_suspend() callbacks woke up a task, which set the
NEED_RESCHED flag. A later callback in the resume path invoked
cond_resched() which in turn led to the invocation of the scheduler:
__cond_resched+0x21/0x60
down_timeout+0x18/0x60
acpi_os_wait_semaphore+0x4c/0x80
acpi_ut_acquire_mutex+0x3d/0x100
acpi_ns_get_node+0x27/0x60
acpi_ns_evaluate+0x1cb/0x2d0
acpi_rs_set_srs_method_data+0x156/0x190
acpi_pci_link_set+0x11c/0x290
irqrouter_resume+0x54/0x60
syscore_resume+0x6a/0x200
kernel_kexec+0x145/0x1c0
__do_sys_reboot+0xeb/0x240
do_syscall_64+0x95/0x180
This is a long standing problem, which probably got more visible with
the recent printk changes. Something does a task wakeup and the
scheduler sets the NEED_RESCHED flag. cond_resched() sees it set and
invokes schedule() from a completely bogus context. The scheduler
enables interrupts after context switching, which causes the above
warning at the end.
Quite some of the code paths in syscore_suspend()/resume() can result in
triggering a wakeup with the exactly same consequences. They might not
have done so yet, but as they share a lot of code with normal operations
it's just a question of time.
The problem only affects the PREEMPT_NONE and PREEMPT_VOLUNTARY scheduling
models. Full preemption is not affected as cond_resched() is disabled and
the preemption check preemptible() takes the interrupt disabled flag into
account.
Cure the problem by adding a corresponding check into cond_resched().
In the Linux kernel, the following vulnerability has been resolved:
USB: gadget: f_midi: f_midi_complete to call queue_work
When using USB MIDI, a lock is attempted to be acquired twice through a
re-entrant call to f_midi_transmit, causing a deadlock.
Fix it by using queue_work() to schedule the inner f_midi_transmit() via
a high priority work queue from the completion handler.