In the Linux kernel, the following vulnerability has been resolved:
md: fix deadlock between mddev_suspend and flush bio
Deadlock occurs when mddev is being suspended while some flush bio is in
progress. It is a complex issue.
T1. the first flush is at the ending stage, it clears 'mddev->flush_bio'
and tries to submit data, but is blocked because mddev is suspended
by T4.
T2. the second flush sets 'mddev->flush_bio', and attempts to queue
md_submit_flush_data(), which is already running (T1) and won't
execute again if on the same CPU as T1.
T3. the third flush inc active_io and tries to flush, but is blocked because
'mddev->flush_bio' is not NULL (set by T2).
T4. mddev_suspend() is called and waits for active_io dec to 0 which is inc
by T3.
T1 T2 T3 T4
(flush 1) (flush 2) (third 3) (suspend)
md_submit_flush_data
mddev->flush_bio = NULL;
.
. md_flush_request
. mddev->flush_bio = bio
. queue submit_flushes
. .
. . md_handle_request
. . active_io + 1
. . md_flush_request
. . wait !mddev->flush_bio
. .
. . mddev_suspend
. . wait !active_io
. .
. submit_flushes
. queue_work md_submit_flush_data
. //md_submit_flush_data is already running (T1)
.
md_handle_request
wait resume
The root issue is non-atomic inc/dec of active_io during flush process.
active_io is dec before md_submit_flush_data is queued, and inc soon
after md_submit_flush_data() run.
md_flush_request
active_io + 1
submit_flushes
active_io - 1
md_submit_flush_data
md_handle_request
active_io + 1
make_request
active_io - 1
If active_io is dec after md_handle_request() instead of within
submit_flushes(), make_request() can be called directly intead of
md_handle_request() in md_submit_flush_data(), and active_io will
only inc and dec once in the whole flush process. Deadlock will be
fixed.
Additionally, the only difference between fixing the issue and before is
that there is no return error handling of make_request(). But after
previous patch cleaned md_write_start(), make_requst() only return error
in raid5_make_request() by dm-raid, see commit 41425f96d7aa ("dm-raid456,
md/raid456: fix a deadlock for dm-raid456 while io concurrent with
reshape)". Since dm always splits data and flush operation into two
separate io, io size of flush submitted by dm always is 0, make_request()
will not be called in md_submit_flush_data(). To prevent future
modifications from introducing issues, add WARN_ON to ensure
make_request() no error is returned in this context.
In the Linux kernel, the following vulnerability has been resolved:
dev/parport: fix the array out-of-bounds risk
Fixed array out-of-bounds issues caused by sprintf
by replacing it with snprintf for safer data copying,
ensuring the destination buffer is not overflowed.
Below is the stack trace I encountered during the actual issue:
[ 66.575408s] [pid:5118,cpu4,QThread,4]Kernel panic - not syncing: stack-protector:
Kernel stack is corrupted in: do_hardware_base_addr+0xcc/0xd0 [parport]
[ 66.575408s] [pid:5118,cpu4,QThread,5]CPU: 4 PID: 5118 Comm:
QThread Tainted: G S W O 5.10.97-arm64-desktop #7100.57021.2
[ 66.575439s] [pid:5118,cpu4,QThread,6]TGID: 5087 Comm: EFileApp
[ 66.575439s] [pid:5118,cpu4,QThread,7]Hardware name: HUAWEI HUAWEI QingYun
PGUX-W515x-B081/SP1PANGUXM, BIOS 1.00.07 04/29/2024
[ 66.575439s] [pid:5118,cpu4,QThread,8]Call trace:
[ 66.575469s] [pid:5118,cpu4,QThread,9] dump_backtrace+0x0/0x1c0
[ 66.575469s] [pid:5118,cpu4,QThread,0] show_stack+0x14/0x20
[ 66.575469s] [pid:5118,cpu4,QThread,1] dump_stack+0xd4/0x10c
[ 66.575500s] [pid:5118,cpu4,QThread,2] panic+0x1d8/0x3bc
[ 66.575500s] [pid:5118,cpu4,QThread,3] __stack_chk_fail+0x2c/0x38
[ 66.575500s] [pid:5118,cpu4,QThread,4] do_hardware_base_addr+0xcc/0xd0 [parport]
In the Linux kernel, the following vulnerability has been resolved:
PCI/DPC: Fix use-after-free on concurrent DPC and hot-removal
Keith reports a use-after-free when a DPC event occurs concurrently to
hot-removal of the same portion of the hierarchy:
The dpc_handler() awaits readiness of the secondary bus below the
Downstream Port where the DPC event occurred. To do so, it polls the
config space of the first child device on the secondary bus. If that
child device is concurrently removed, accesses to its struct pci_dev
cause the kernel to oops.
That's because pci_bridge_wait_for_secondary_bus() neglects to hold a
reference on the child device. Before v6.3, the function was only
called on resume from system sleep or on runtime resume. Holding a
reference wasn't necessary back then because the pciehp IRQ thread
could never run concurrently. (On resume from system sleep, IRQs are
not enabled until after the resume_noirq phase. And runtime resume is
always awaited before a PCI device is removed.)
However starting with v6.3, pci_bridge_wait_for_secondary_bus() is also
called on a DPC event. Commit 53b54ad074de ("PCI/DPC: Await readiness
of secondary bus after reset"), which introduced that, failed to
appreciate that pci_bridge_wait_for_secondary_bus() now needs to hold a
reference on the child device because dpc_handler() and pciehp may
indeed run concurrently. The commit was backported to v5.10+ stable
kernels, so that's the oldest one affected.
Add the missing reference acquisition.
Abridged stack trace:
BUG: unable to handle page fault for address: 00000000091400c0
CPU: 15 PID: 2464 Comm: irq/53-pcie-dpc 6.9.0
RIP: pci_bus_read_config_dword+0x17/0x50
pci_dev_wait()
pci_bridge_wait_for_secondary_bus()
dpc_reset_link()
pcie_do_recovery()
dpc_handler()
In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: Fix for possible memory corruption
Init Control Block is dereferenced incorrectly. Correctly dereference ICB
In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: During vport delete send async logout explicitly
During vport delete, it is observed that during unload we hit a crash
because of stale entries in outstanding command array. For all these stale
I/O entries, eh_abort was issued and aborted (fast_fail_io = 2009h) but
I/Os could not complete while vport delete is in process of deleting.
BUG: kernel NULL pointer dereference, address: 000000000000001c
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
Workqueue: qla2xxx_wq qla_do_work [qla2xxx]
RIP: 0010:dma_direct_unmap_sg+0x51/0x1e0
RSP: 0018:ffffa1e1e150fc68 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000021 RCX: 0000000000000001
RDX: 0000000000000021 RSI: 0000000000000000 RDI: ffff8ce208a7a0d0
RBP: ffff8ce208a7a0d0 R08: 0000000000000000 R09: ffff8ce378aac9c8
R10: ffff8ce378aac8a0 R11: ffffa1e1e150f9d8 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8ce378aac9c8 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8d217f000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000001c CR3: 0000002089acc000 CR4: 0000000000350ee0
Call Trace:
<TASK>
qla2xxx_qpair_sp_free_dma+0x417/0x4e0
? qla2xxx_qpair_sp_compl+0x10d/0x1a0
? qla2x00_status_entry+0x768/0x2830
? newidle_balance+0x2f0/0x430
? dequeue_entity+0x100/0x3c0
? qla24xx_process_response_queue+0x6a1/0x19e0
? __schedule+0x2d5/0x1140
? qla_do_work+0x47/0x60
? process_one_work+0x267/0x440
? process_one_work+0x440/0x440
? worker_thread+0x2d/0x3d0
? process_one_work+0x440/0x440
? kthread+0x156/0x180
? set_kthread_struct+0x50/0x50
? ret_from_fork+0x22/0x30
</TASK>
Send out async logout explicitly for all the ports during vport delete.