| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
md/raid10: prevent soft lockup while flush writes
Currently, there is no limit for raid1/raid10 plugged bio. While flushing
writes, raid1 has cond_resched() while raid10 doesn't, and too many
writes can cause soft lockup.
Follow up soft lockup can be triggered easily with writeback test for
raid10 with ramdisks:
watchdog: BUG: soft lockup - CPU#10 stuck for 27s! [md0_raid10:1293]
Call Trace:
<TASK>
call_rcu+0x16/0x20
put_object+0x41/0x80
__delete_object+0x50/0x90
delete_object_full+0x2b/0x40
kmemleak_free+0x46/0xa0
slab_free_freelist_hook.constprop.0+0xed/0x1a0
kmem_cache_free+0xfd/0x300
mempool_free_slab+0x1f/0x30
mempool_free+0x3a/0x100
bio_free+0x59/0x80
bio_put+0xcf/0x2c0
free_r10bio+0xbf/0xf0
raid_end_bio_io+0x78/0xb0
one_write_done+0x8a/0xa0
raid10_end_write_request+0x1b4/0x430
bio_endio+0x175/0x320
brd_submit_bio+0x3b9/0x9b7 [brd]
__submit_bio+0x69/0xe0
submit_bio_noacct_nocheck+0x1e6/0x5a0
submit_bio_noacct+0x38c/0x7e0
flush_pending_writes+0xf0/0x240
raid10d+0xac/0x1ed0
Fix the problem by adding cond_resched() to raid10 like what raid1 did.
Note that unlimited plugged bio still need to be optimized, for example,
in the case of lots of dirty pages writeback, this will take lots of
memory and io will spend a long time in plug, hence io latency is bad. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: Pointer may be dereferenced
Klocwork tool reported pointer 'rport' returned from call to function
fc_bsg_to_rport() may be NULL and will be dereferenced.
Add a fix to validate rport before dereferencing. |
| In the Linux kernel, the following vulnerability has been resolved:
igb: Fix igb_down hung on surprise removal
In a setup where a Thunderbolt hub connects to Ethernet and a display
through USB Type-C, users may experience a hung task timeout when they
remove the cable between the PC and the Thunderbolt hub.
This is because the igb_down function is called multiple times when
the Thunderbolt hub is unplugged. For example, the igb_io_error_detected
triggers the first call, and the igb_remove triggers the second call.
The second call to igb_down will block at napi_synchronize.
Here's the call trace:
__schedule+0x3b0/0xddb
? __mod_timer+0x164/0x5d3
schedule+0x44/0xa8
schedule_timeout+0xb2/0x2a4
? run_local_timers+0x4e/0x4e
msleep+0x31/0x38
igb_down+0x12c/0x22a [igb 6615058754948bfde0bf01429257eb59f13030d4]
__igb_close+0x6f/0x9c [igb 6615058754948bfde0bf01429257eb59f13030d4]
igb_close+0x23/0x2b [igb 6615058754948bfde0bf01429257eb59f13030d4]
__dev_close_many+0x95/0xec
dev_close_many+0x6e/0x103
unregister_netdevice_many+0x105/0x5b1
unregister_netdevice_queue+0xc2/0x10d
unregister_netdev+0x1c/0x23
igb_remove+0xa7/0x11c [igb 6615058754948bfde0bf01429257eb59f13030d4]
pci_device_remove+0x3f/0x9c
device_release_driver_internal+0xfe/0x1b4
pci_stop_bus_device+0x5b/0x7f
pci_stop_bus_device+0x30/0x7f
pci_stop_bus_device+0x30/0x7f
pci_stop_and_remove_bus_device+0x12/0x19
pciehp_unconfigure_device+0x76/0xe9
pciehp_disable_slot+0x6e/0x131
pciehp_handle_presence_or_link_change+0x7a/0x3f7
pciehp_ist+0xbe/0x194
irq_thread_fn+0x22/0x4d
? irq_thread+0x1fd/0x1fd
irq_thread+0x17b/0x1fd
? irq_forced_thread_fn+0x5f/0x5f
kthread+0x142/0x153
? __irq_get_irqchip_state+0x46/0x46
? kthread_associate_blkcg+0x71/0x71
ret_from_fork+0x1f/0x30
In this case, igb_io_error_detected detaches the network interface
and requests a PCIE slot reset, however, the PCIE reset callback is
not being invoked and thus the Ethernet connection breaks down.
As the PCIE error in this case is a non-fatal one, requesting a
slot reset can be avoided.
This patch fixes the task hung issue and preserves Ethernet
connection by ignoring non-fatal PCIE errors. |
| In the Linux kernel, the following vulnerability has been resolved:
media: dw2102: Fix null-ptr-deref in dw2102_i2c_transfer()
In dw2102_i2c_transfer, msg is controlled by user. When msg[i].buf
is null and msg[i].len is zero, former checks on msg[i].buf would be
passed. Malicious data finally reach dw2102_i2c_transfer. If accessing
msg[i].buf[0] without sanity check, null ptr deref would happen.
We add check on msg[i].len to prevent crash.
Similar commit:
commit 950e252cb469
("[media] dw2102: limit messages to buffer size") |
| In the Linux kernel, the following vulnerability has been resolved:
fs: prevent out-of-bounds array speculation when closing a file descriptor
Google-Bug-Id: 114199369 |
| In the Linux kernel, the following vulnerability has been resolved:
media: rc: gpio-ir-recv: add remove function
In case runtime PM is enabled, do runtime PM clean up to remove
cpu latency qos request, otherwise driver removal may have below
kernel dump:
[ 19.463299] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000048
[ 19.472161] Mem abort info:
[ 19.474985] ESR = 0x0000000096000004
[ 19.478754] EC = 0x25: DABT (current EL), IL = 32 bits
[ 19.484081] SET = 0, FnV = 0
[ 19.487149] EA = 0, S1PTW = 0
[ 19.490361] FSC = 0x04: level 0 translation fault
[ 19.495256] Data abort info:
[ 19.498149] ISV = 0, ISS = 0x00000004
[ 19.501997] CM = 0, WnR = 0
[ 19.504977] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000049f81000
[ 19.511432] [0000000000000048] pgd=0000000000000000,
p4d=0000000000000000
[ 19.518245] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[ 19.524520] Modules linked in: gpio_ir_recv(+) rc_core [last
unloaded: rc_core]
[ 19.531845] CPU: 0 PID: 445 Comm: insmod Not tainted
6.2.0-rc1-00028-g2c397a46d47c #72
[ 19.531854] Hardware name: FSL i.MX8MM EVK board (DT)
[ 19.531859] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS
BTYPE=--)
[ 19.551777] pc : cpu_latency_qos_remove_request+0x20/0x110
[ 19.557277] lr : gpio_ir_recv_runtime_suspend+0x18/0x30
[gpio_ir_recv]
[ 19.557294] sp : ffff800008ce3740
[ 19.557297] x29: ffff800008ce3740 x28: 0000000000000000 x27:
ffff800008ce3d50
[ 19.574270] x26: ffffc7e3e9cea100 x25: 00000000000f4240 x24:
ffffc7e3f9ef0e30
[ 19.574284] x23: 0000000000000000 x22: ffff0061803820f4 x21:
0000000000000008
[ 19.574296] x20: ffffc7e3fa75df30 x19: 0000000000000020 x18:
ffffffffffffffff
[ 19.588570] x17: 0000000000000000 x16: ffffc7e3f9efab70 x15:
ffffffffffffffff
[ 19.595712] x14: ffff800008ce37b8 x13: ffff800008ce37aa x12:
0000000000000001
[ 19.602853] x11: 0000000000000001 x10: ffffcbe3ec0dff87 x9 :
0000000000000008
[ 19.609991] x8 : 0101010101010101 x7 : 0000000000000000 x6 :
000000000f0bfe9f
[ 19.624261] x5 : 00ffffffffffffff x4 : 0025ab8e00000000 x3 :
ffff006180382010
[ 19.631405] x2 : ffffc7e3e9ce8030 x1 : ffffc7e3fc3eb810 x0 :
0000000000000020
[ 19.638548] Call trace:
[ 19.640995] cpu_latency_qos_remove_request+0x20/0x110
[ 19.646142] gpio_ir_recv_runtime_suspend+0x18/0x30 [gpio_ir_recv]
[ 19.652339] pm_generic_runtime_suspend+0x2c/0x44
[ 19.657055] __rpm_callback+0x48/0x1dc
[ 19.660807] rpm_callback+0x6c/0x80
[ 19.664301] rpm_suspend+0x10c/0x640
[ 19.667880] rpm_idle+0x250/0x2d0
[ 19.671198] update_autosuspend+0x38/0xe0
[ 19.675213] pm_runtime_set_autosuspend_delay+0x40/0x60
[ 19.680442] gpio_ir_recv_probe+0x1b4/0x21c [gpio_ir_recv]
[ 19.685941] platform_probe+0x68/0xc0
[ 19.689610] really_probe+0xc0/0x3dc
[ 19.693189] __driver_probe_device+0x7c/0x190
[ 19.697550] driver_probe_device+0x3c/0x110
[ 19.701739] __driver_attach+0xf4/0x200
[ 19.705578] bus_for_each_dev+0x70/0xd0
[ 19.709417] driver_attach+0x24/0x30
[ 19.712998] bus_add_driver+0x17c/0x240
[ 19.716834] driver_register+0x78/0x130
[ 19.720676] __platform_driver_register+0x28/0x34
[ 19.725386] gpio_ir_recv_driver_init+0x20/0x1000 [gpio_ir_recv]
[ 19.731404] do_one_initcall+0x44/0x2ac
[ 19.735243] do_init_module+0x48/0x1d0
[ 19.739003] load_module+0x19fc/0x2034
[ 19.742759] __do_sys_finit_module+0xac/0x12c
[ 19.747124] __arm64_sys_finit_module+0x20/0x30
[ 19.751664] invoke_syscall+0x48/0x114
[ 19.755420] el0_svc_common.constprop.0+0xcc/0xec
[ 19.760132] do_el0_svc+0x38/0xb0
[ 19.763456] el0_svc+0x2c/0x84
[ 19.766516] el0t_64_sync_handler+0xf4/0x120
[ 19.770789] el0t_64_sync+0x190/0x194
[ 19.774460] Code: 910003fd a90153f3 aa0003f3 91204021 (f9401400)
[ 19.780556] ---[ end trace 0000000000000000 ]--- |
| In the Linux kernel, the following vulnerability has been resolved:
powerpc/iommu: 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:
ca8210: fix mac_len negative array access
This patch fixes a buffer overflow access of skb->data if
ieee802154_hdr_peek_addrs() fails. |
| In the Linux kernel, the following vulnerability has been resolved:
cifs: fix potential memory leaks in session setup
Make sure to free cifs_ses::auth_key.response before allocating it as
we might end up leaking memory in reconnect or mounting. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: iscsi_tcp: Fix UAF during login when accessing the shost ipaddress
If during iscsi_sw_tcp_session_create() iscsi_tcp_r2tpool_alloc() fails,
userspace could be accessing the host's ipaddress attr. If we then free the
session via iscsi_session_teardown() while userspace is still accessing the
session we will hit a use after free bug.
Set the tcp_sw_host->session after we have completed session creation and
can no longer fail. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/swapfile: add cond_resched() in get_swap_pages()
The softlockup still occurs in get_swap_pages() under memory pressure. 64
CPU cores, 64GB memory, and 28 zram devices, the disksize of each zram
device is 50MB with same priority as si. Use the stress-ng tool to
increase memory pressure, causing the system to oom frequently.
The plist_for_each_entry_safe() loops in get_swap_pages() could reach tens
of thousands of times to find available space (extreme case:
cond_resched() is not called in scan_swap_map_slots()). Let's add
cond_resched() into get_swap_pages() when failed to find available space
to avoid softlockup. |
| In the Linux kernel, the following vulnerability has been resolved:
media: pci: cx23885: check cx23885_vdev_init() return
cx23885_vdev_init() can return a NULL pointer, but that pointer
is used in the next line without a check.
Add a NULL pointer check and go to the error unwind if it is NULL. |
| In the Linux kernel, the following vulnerability has been resolved:
media: dvb-usb-v2: af9035: Fix null-ptr-deref in af9035_i2c_master_xfer
In af9035_i2c_master_xfer, msg is controlled by user. When msg[i].buf
is null and msg[i].len is zero, former checks on msg[i].buf would be
passed. Malicious data finally reach af9035_i2c_master_xfer. If accessing
msg[i].buf[0] without sanity check, null ptr deref would happen.
We add check on msg[i].len to prevent crash.
Similar commit:
commit 0ed554fd769a
("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()") |
| In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix general protection fault in nilfs_btree_insert()
If nilfs2 reads a corrupted disk image and tries to reads a b-tree node
block by calling __nilfs_btree_get_block() against an invalid virtual
block address, it returns -ENOENT because conversion of the virtual block
address to a disk block address fails. However, this return value is the
same as the internal code that b-tree lookup routines return to indicate
that the block being searched does not exist, so functions that operate on
that b-tree may misbehave.
When nilfs_btree_insert() receives this spurious 'not found' code from
nilfs_btree_do_lookup(), it misunderstands that the 'not found' check was
successful and continues the insert operation using incomplete lookup path
data, causing the following crash:
general protection fault, probably for non-canonical address
0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
...
RIP: 0010:nilfs_btree_get_nonroot_node fs/nilfs2/btree.c:418 [inline]
RIP: 0010:nilfs_btree_prepare_insert fs/nilfs2/btree.c:1077 [inline]
RIP: 0010:nilfs_btree_insert+0x6d3/0x1c10 fs/nilfs2/btree.c:1238
Code: bc 24 80 00 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89
ff e8 4b 02 92 fe 4d 8b 3f 49 83 c7 28 4c 89 f8 48 c1 e8 03 <42> 80 3c
28 00 74 08 4c 89 ff e8 2e 02 92 fe 4d 8b 3f 49 83 c7 02
...
Call Trace:
<TASK>
nilfs_bmap_do_insert fs/nilfs2/bmap.c:121 [inline]
nilfs_bmap_insert+0x20d/0x360 fs/nilfs2/bmap.c:147
nilfs_get_block+0x414/0x8d0 fs/nilfs2/inode.c:101
__block_write_begin_int+0x54c/0x1a80 fs/buffer.c:1991
__block_write_begin fs/buffer.c:2041 [inline]
block_write_begin+0x93/0x1e0 fs/buffer.c:2102
nilfs_write_begin+0x9c/0x110 fs/nilfs2/inode.c:261
generic_perform_write+0x2e4/0x5e0 mm/filemap.c:3772
__generic_file_write_iter+0x176/0x400 mm/filemap.c:3900
generic_file_write_iter+0xab/0x310 mm/filemap.c:3932
call_write_iter include/linux/fs.h:2186 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x7dc/0xc50 fs/read_write.c:584
ksys_write+0x177/0x2a0 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
...
</TASK>
This patch fixes the root cause of this problem by replacing the error
code that __nilfs_btree_get_block() returns on block address conversion
failure from -ENOENT to another internal code -EINVAL which means that the
b-tree metadata is corrupted.
By returning -EINVAL, it propagates without glitches, and for all relevant
b-tree operations, functions in the upper bmap layer output an error
message indicating corrupted b-tree metadata via
nilfs_bmap_convert_error(), and code -EIO will be eventually returned as
it should be. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_ncm: fix potential NULL ptr deref in ncm_bitrate()
In Google internal bug 265639009 we've received an (as yet) unreproducible
crash report from an aarch64 GKI 5.10.149-android13 running device.
AFAICT the source code is at:
https://android.googlesource.com/kernel/common/+/refs/tags/ASB-2022-12-05_13-5.10
The call stack is:
ncm_close() -> ncm_notify() -> ncm_do_notify()
with the crash at:
ncm_do_notify+0x98/0x270
Code: 79000d0b b9000a6c f940012a f9400269 (b9405d4b)
Which I believe disassembles to (I don't know ARM assembly, but it looks sane enough to me...):
// halfword (16-bit) store presumably to event->wLength (at offset 6 of struct usb_cdc_notification)
0B 0D 00 79 strh w11, [x8, #6]
// word (32-bit) store presumably to req->Length (at offset 8 of struct usb_request)
6C 0A 00 B9 str w12, [x19, #8]
// x10 (NULL) was read here from offset 0 of valid pointer x9
// IMHO we're reading 'cdev->gadget' and getting NULL
// gadget is indeed at offset 0 of struct usb_composite_dev
2A 01 40 F9 ldr x10, [x9]
// loading req->buf pointer, which is at offset 0 of struct usb_request
69 02 40 F9 ldr x9, [x19]
// x10 is null, crash, appears to be attempt to read cdev->gadget->max_speed
4B 5D 40 B9 ldr w11, [x10, #0x5c]
which seems to line up with ncm_do_notify() case NCM_NOTIFY_SPEED code fragment:
event->wLength = cpu_to_le16(8);
req->length = NCM_STATUS_BYTECOUNT;
/* SPEED_CHANGE data is up/down speeds in bits/sec */
data = req->buf + sizeof *event;
data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
My analysis of registers and NULL ptr deref crash offset
(Unable to handle kernel NULL pointer dereference at virtual address 000000000000005c)
heavily suggests that the crash is due to 'cdev->gadget' being NULL when executing:
data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
which calls:
ncm_bitrate(NULL)
which then calls:
gadget_is_superspeed(NULL)
which reads
((struct usb_gadget *)NULL)->max_speed
and hits a panic.
AFAICT, if I'm counting right, the offset of max_speed is indeed 0x5C.
(remember there's a GKI KABI reservation of 16 bytes in struct work_struct)
It's not at all clear to me how this is all supposed to work...
but returning 0 seems much better than panic-ing... |
| In the Linux kernel, the following vulnerability has been resolved:
locking/ww_mutex/test: Fix potential workqueue corruption
In some cases running with the test-ww_mutex code, I was seeing
odd behavior where sometimes it seemed flush_workqueue was
returning before all the work threads were finished.
Often this would cause strange crashes as the mutexes would be
freed while they were being used.
Looking at the code, there is a lifetime problem as the
controlling thread that spawns the work allocates the
"struct stress" structures that are passed to the workqueue
threads. Then when the workqueue threads are finished,
they free the stress struct that was passed to them.
Unfortunately the workqueue work_struct node is in the stress
struct. Which means the work_struct is freed before the work
thread returns and while flush_workqueue is waiting.
It seems like a better idea to have the controlling thread
both allocate and free the stress structures, so that we can
be sure we don't corrupt the workqueue by freeing the structure
prematurely.
So this patch reworks the test to do so, and with this change
I no longer see the early flush_workqueue returns. |
| In the Linux kernel, the following vulnerability has been resolved:
perf/core: Bail out early if the request AUX area is out of bound
When perf-record with a large AUX area, e.g 4GB, it fails with:
#perf record -C 0 -m ,4G -e arm_spe_0// -- sleep 1
failed to mmap with 12 (Cannot allocate memory)
and it reveals a WARNING with __alloc_pages():
------------[ cut here ]------------
WARNING: CPU: 44 PID: 17573 at mm/page_alloc.c:5568 __alloc_pages+0x1ec/0x248
Call trace:
__alloc_pages+0x1ec/0x248
__kmalloc_large_node+0xc0/0x1f8
__kmalloc_node+0x134/0x1e8
rb_alloc_aux+0xe0/0x298
perf_mmap+0x440/0x660
mmap_region+0x308/0x8a8
do_mmap+0x3c0/0x528
vm_mmap_pgoff+0xf4/0x1b8
ksys_mmap_pgoff+0x18c/0x218
__arm64_sys_mmap+0x38/0x58
invoke_syscall+0x50/0x128
el0_svc_common.constprop.0+0x58/0x188
do_el0_svc+0x34/0x50
el0_svc+0x34/0x108
el0t_64_sync_handler+0xb8/0xc0
el0t_64_sync+0x1a4/0x1a8
'rb->aux_pages' allocated by kcalloc() is a pointer array which is used to
maintains AUX trace pages. The allocated page for this array is physically
contiguous (and virtually contiguous) with an order of 0..MAX_ORDER. If the
size of pointer array crosses the limitation set by MAX_ORDER, it reveals a
WARNING.
So bail out early with -ENOMEM if the request AUX area is out of bound,
e.g.:
#perf record -C 0 -m ,4G -e arm_spe_0// -- sleep 1
failed to mmap with 12 (Cannot allocate memory) |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btusb: Add date->evt_skb is NULL check
fix crash because of null pointers
[ 6104.969662] BUG: kernel NULL pointer dereference, address: 00000000000000c8
[ 6104.969667] #PF: supervisor read access in kernel mode
[ 6104.969668] #PF: error_code(0x0000) - not-present page
[ 6104.969670] PGD 0 P4D 0
[ 6104.969673] Oops: 0000 [#1] SMP NOPTI
[ 6104.969684] RIP: 0010:btusb_mtk_hci_wmt_sync+0x144/0x220 [btusb]
[ 6104.969688] RSP: 0018:ffffb8d681533d48 EFLAGS: 00010246
[ 6104.969689] RAX: 0000000000000000 RBX: ffff8ad560bb2000 RCX: 0000000000000006
[ 6104.969691] RDX: 0000000000000000 RSI: ffffb8d681533d08 RDI: 0000000000000000
[ 6104.969692] RBP: ffffb8d681533d70 R08: 0000000000000001 R09: 0000000000000001
[ 6104.969694] R10: 0000000000000001 R11: 00000000fa83b2da R12: ffff8ad461d1d7c0
[ 6104.969695] R13: 0000000000000000 R14: ffff8ad459618c18 R15: ffffb8d681533d90
[ 6104.969697] FS: 00007f5a1cab9d40(0000) GS:ffff8ad578200000(0000) knlGS:00000
[ 6104.969699] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 6104.969700] CR2: 00000000000000c8 CR3: 000000018620c001 CR4: 0000000000760ef0
[ 6104.969701] PKRU: 55555554
[ 6104.969702] Call Trace:
[ 6104.969708] btusb_mtk_shutdown+0x44/0x80 [btusb]
[ 6104.969732] hci_dev_do_close+0x470/0x5c0 [bluetooth]
[ 6104.969748] hci_rfkill_set_block+0x56/0xa0 [bluetooth]
[ 6104.969753] rfkill_set_block+0x92/0x160
[ 6104.969755] rfkill_fop_write+0x136/0x1e0
[ 6104.969759] __vfs_write+0x18/0x40
[ 6104.969761] vfs_write+0xdf/0x1c0
[ 6104.969763] ksys_write+0xb1/0xe0
[ 6104.969765] __x64_sys_write+0x1a/0x20
[ 6104.969769] do_syscall_64+0x51/0x180
[ 6104.969771] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 6104.969773] RIP: 0033:0x7f5a21f18fef
[ 6104.9] RSP: 002b:00007ffeefe39010 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
[ 6104.969780] RAX: ffffffffffffffda RBX: 000055c10a7560a0 RCX: 00007f5a21f18fef
[ 6104.969781] RDX: 0000000000000008 RSI: 00007ffeefe39060 RDI: 0000000000000012
[ 6104.969782] RBP: 00007ffeefe39060 R08: 0000000000000000 R09: 0000000000000017
[ 6104.969784] R10: 00007ffeefe38d97 R11: 0000000000000293 R12: 0000000000000002
[ 6104.969785] R13: 00007ffeefe39220 R14: 00007ffeefe391a0 R15: 000055c10a72acf0 |
| In the Linux kernel, the following vulnerability has been resolved:
cpu/hotplug: Don't offline the last non-isolated CPU
If a system has isolated CPUs via the "isolcpus=" command line parameter,
then an attempt to offline the last housekeeping CPU will result in a
WARN_ON() when rebuilding the scheduler domains and a subsequent panic due
to and unhandled empty CPU mas in partition_sched_domains_locked().
cpuset_hotplug_workfn()
rebuild_sched_domains_locked()
ndoms = generate_sched_domains(&doms, &attr);
cpumask_and(doms[0], top_cpuset.effective_cpus, housekeeping_cpumask(HK_FLAG_DOMAIN));
Thus results in an empty CPU mask which triggers the warning and then the
subsequent crash:
WARNING: CPU: 4 PID: 80 at kernel/sched/topology.c:2366 build_sched_domains+0x120c/0x1408
Call trace:
build_sched_domains+0x120c/0x1408
partition_sched_domains_locked+0x234/0x880
rebuild_sched_domains_locked+0x37c/0x798
rebuild_sched_domains+0x30/0x58
cpuset_hotplug_workfn+0x2a8/0x930
Unable to handle kernel paging request at virtual address fffe80027ab37080
partition_sched_domains_locked+0x318/0x880
rebuild_sched_domains_locked+0x37c/0x798
Aside of the resulting crash, it does not make any sense to offline the last
last housekeeping CPU.
Prevent this by masking out the non-housekeeping CPUs when selecting a
target CPU for initiating the CPU unplug operation via the work queue. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Detect IP == ksym.end as part of BPF program
Now that bpf_throw kfunc is the first such call instruction that has
noreturn semantics within the verifier, this also kicks in dead code
elimination in unprecedented ways. For one, any instruction following
a bpf_throw call will never be marked as seen. Moreover, if a callchain
ends up throwing, any instructions after the call instruction to the
eventually throwing subprog in callers will also never be marked as
seen.
The tempting way to fix this would be to emit extra 'int3' instructions
which bump the jited_len of a program, and ensure that during runtime
when a program throws, we can discover its boundaries even if the call
instruction to bpf_throw (or to subprogs that always throw) is emitted
as the final instruction in the program.
An example of such a program would be this:
do_something():
...
r0 = 0
exit
foo():
r1 = 0
call bpf_throw
r0 = 0
exit
bar(cond):
if r1 != 0 goto pc+2
call do_something
exit
call foo
r0 = 0 // Never seen by verifier
exit //
main(ctx):
r1 = ...
call bar
r0 = 0
exit
Here, if we do end up throwing, the stacktrace would be the following:
bpf_throw
foo
bar
main
In bar, the final instruction emitted will be the call to foo, as such,
the return address will be the subsequent instruction (which the JIT
emits as int3 on x86). This will end up lying outside the jited_len of
the program, thus, when unwinding, we will fail to discover the return
address as belonging to any program and end up in a panic due to the
unreliable stack unwinding of BPF programs that we never expect.
To remedy this case, make bpf_prog_ksym_find treat IP == ksym.end as
part of the BPF program, so that is_bpf_text_address returns true when
such a case occurs, and we are able to unwind reliably when the final
instruction ends up being a call instruction. |
