In the Linux kernel, the following vulnerability has been resolved:
serial: protect uart_port_dtr_rts() in uart_shutdown() too
Commit af224ca2df29 (serial: core: Prevent unsafe uart port access, part
3) added few uport == NULL checks. It added one to uart_shutdown(), so
the commit assumes, uport can be NULL in there. But right after that
protection, there is an unprotected "uart_port_dtr_rts(uport, false);"
call. That is invoked only if HUPCL is set, so I assume that is the
reason why we do not see lots of these reports.
Or it cannot be NULL at this point at all for some reason :P.
Until the above is investigated, stay on the safe side and move this
dereference to the if too.
I got this inconsistency from Coverity under CID 1585130. Thanks.
In the Linux kernel, the following vulnerability has been resolved:
net: phy: fix null-ptr-deref while probe() failed
I got a null-ptr-deref report as following when doing fault injection test:
BUG: kernel NULL pointer dereference, address: 0000000000000058
Oops: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 PID: 253 Comm: 507-spi-dm9051 Tainted: G B N 6.1.0-rc3+
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:klist_put+0x2d/0xd0
Call Trace:
<TASK>
klist_remove+0xf1/0x1c0
device_release_driver_internal+0x23e/0x2d0
bus_remove_device+0x1bd/0x240
device_del+0x357/0x770
phy_device_remove+0x11/0x30
mdiobus_unregister+0xa5/0x140
release_nodes+0x6a/0xa0
devres_release_all+0xf8/0x150
device_unbind_cleanup+0x19/0xd0
//probe path:
phy_device_register()
device_add()
phy_connect
phy_attach_direct() //set device driver
probe() //it's failed, driver is not bound
device_bind_driver() // probe failed, it's not called
//remove path:
phy_device_remove()
device_del()
device_release_driver_internal()
__device_release_driver() //dev->drv is not NULL
klist_remove() <- knode_driver is not added yet, cause null-ptr-deref
In phy_attach_direct(), after setting the 'dev->driver', probe() fails,
device_bind_driver() is not called, so the knode_driver->n_klist is not
set, then it causes null-ptr-deref in __device_release_driver() while
deleting device. Fix this by setting dev->driver to NULL in the error
path in phy_attach_direct().
In the Linux kernel, the following vulnerability has been resolved:
btrfs: qgroup: fix sleep from invalid context bug in btrfs_qgroup_inherit()
Syzkaller reported BUG as follows:
BUG: sleeping function called from invalid context at
include/linux/sched/mm.h:274
Call Trace:
<TASK>
dump_stack_lvl+0xcd/0x134
__might_resched.cold+0x222/0x26b
kmem_cache_alloc+0x2e7/0x3c0
update_qgroup_limit_item+0xe1/0x390
btrfs_qgroup_inherit+0x147b/0x1ee0
create_subvol+0x4eb/0x1710
btrfs_mksubvol+0xfe5/0x13f0
__btrfs_ioctl_snap_create+0x2b0/0x430
btrfs_ioctl_snap_create_v2+0x25a/0x520
btrfs_ioctl+0x2a1c/0x5ce0
__x64_sys_ioctl+0x193/0x200
do_syscall_64+0x35/0x80
Fix this by calling qgroup_dirty() on @dstqgroup, and update limit item in
btrfs_run_qgroups() later outside of the spinlock context.
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix NULL pointer dereference in nilfs_palloc_commit_free_entry()
Syzbot reported a null-ptr-deref bug:
NILFS (loop0): segctord starting. Construction interval = 5 seconds, CP
frequency < 30 seconds
general protection fault, probably for non-canonical address
0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 1 PID: 3603 Comm: segctord Not tainted
6.1.0-rc2-syzkaller-00105-gb229b6ca5abb #0
Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google
10/11/2022
RIP: 0010:nilfs_palloc_commit_free_entry+0xe5/0x6b0
fs/nilfs2/alloc.c:608
Code: 00 00 00 00 fc ff df 80 3c 02 00 0f 85 cd 05 00 00 48 b8 00 00 00
00 00 fc ff df 4c 8b 73 08 49 8d 7e 10 48 89 fa 48 c1 ea 03 <80> 3c 02
00 0f 85 26 05 00 00 49 8b 46 10 be a6 00 00 00 48 c7 c7
RSP: 0018:ffffc90003dff830 EFLAGS: 00010212
RAX: dffffc0000000000 RBX: ffff88802594e218 RCX: 000000000000000d
RDX: 0000000000000002 RSI: 0000000000002000 RDI: 0000000000000010
RBP: ffff888071880222 R08: 0000000000000005 R09: 000000000000003f
R10: 000000000000000d R11: 0000000000000000 R12: ffff888071880158
R13: ffff88802594e220 R14: 0000000000000000 R15: 0000000000000004
FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb1c08316a8 CR3: 0000000018560000 CR4: 0000000000350ee0
Call Trace:
<TASK>
nilfs_dat_commit_free fs/nilfs2/dat.c:114 [inline]
nilfs_dat_commit_end+0x464/0x5f0 fs/nilfs2/dat.c:193
nilfs_dat_commit_update+0x26/0x40 fs/nilfs2/dat.c:236
nilfs_btree_commit_update_v+0x87/0x4a0 fs/nilfs2/btree.c:1940
nilfs_btree_commit_propagate_v fs/nilfs2/btree.c:2016 [inline]
nilfs_btree_propagate_v fs/nilfs2/btree.c:2046 [inline]
nilfs_btree_propagate+0xa00/0xd60 fs/nilfs2/btree.c:2088
nilfs_bmap_propagate+0x73/0x170 fs/nilfs2/bmap.c:337
nilfs_collect_file_data+0x45/0xd0 fs/nilfs2/segment.c:568
nilfs_segctor_apply_buffers+0x14a/0x470 fs/nilfs2/segment.c:1018
nilfs_segctor_scan_file+0x3f4/0x6f0 fs/nilfs2/segment.c:1067
nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1197 [inline]
nilfs_segctor_collect fs/nilfs2/segment.c:1503 [inline]
nilfs_segctor_do_construct+0x12fc/0x6af0 fs/nilfs2/segment.c:2045
nilfs_segctor_construct+0x8e3/0xb30 fs/nilfs2/segment.c:2379
nilfs_segctor_thread_construct fs/nilfs2/segment.c:2487 [inline]
nilfs_segctor_thread+0x3c3/0xf30 fs/nilfs2/segment.c:2570
kthread+0x2e4/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>
...
If DAT metadata file is corrupted on disk, there is a case where
req->pr_desc_bh is NULL and blocknr is 0 at nilfs_dat_commit_end() during
a b-tree operation that cascadingly updates ancestor nodes of the b-tree,
because nilfs_dat_commit_alloc() for a lower level block can initialize
the blocknr on the same DAT entry between nilfs_dat_prepare_end() and
nilfs_dat_commit_end().
If this happens, nilfs_dat_commit_end() calls nilfs_dat_commit_free()
without valid buffer heads in req->pr_desc_bh and req->pr_bitmap_bh, and
causes the NULL pointer dereference above in
nilfs_palloc_commit_free_entry() function, which leads to a crash.
Fix this by adding a NULL check on req->pr_desc_bh and req->pr_bitmap_bh
before nilfs_palloc_commit_free_entry() in nilfs_dat_commit_free().
This also calls nilfs_error() in that case to notify that there is a fatal
flaw in the filesystem metadata and prevent further operations.
In the Linux kernel, the following vulnerability has been resolved:
ASoC: soc-pcm: Add NULL check in BE reparenting
Add NULL check in dpcm_be_reparent API, to handle
kernel NULL pointer dereference error.
The issue occurred in fuzzing test.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: seq: Fix function prototype mismatch in snd_seq_expand_var_event
With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG),
indirect call targets are validated against the expected function
pointer prototype to make sure the call target is valid to help mitigate
ROP attacks. If they are not identical, there is a failure at run time,
which manifests as either a kernel panic or thread getting killed.
seq_copy_in_user() and seq_copy_in_kernel() did not have prototypes
matching snd_seq_dump_func_t. Adjust this and remove the casts. There
are not resulting binary output differences.
This was found as a result of Clang's new -Wcast-function-type-strict
flag, which is more sensitive than the simpler -Wcast-function-type,
which only checks for type width mismatches.
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: fix use-after-free during gpu recovery
[Why]
[ 754.862560] refcount_t: underflow; use-after-free.
[ 754.862898] Call Trace:
[ 754.862903] <TASK>
[ 754.862913] amdgpu_job_free_cb+0xc2/0xe1 [amdgpu]
[ 754.863543] drm_sched_main.cold+0x34/0x39 [amd_sched]
[How]
The fw_fence may be not init, check whether dma_fence_init
is performed before job free
In the Linux kernel, the following vulnerability has been resolved:
HID: core: fix shift-out-of-bounds in hid_report_raw_event
Syzbot reported shift-out-of-bounds in hid_report_raw_event.
microsoft 0003:045E:07DA.0001: hid_field_extract() called with n (128) >
32! (swapper/0)
======================================================================
UBSAN: shift-out-of-bounds in drivers/hid/hid-core.c:1323:20
shift exponent 127 is too large for 32-bit type 'int'
CPU: 0 PID: 0 Comm: swapper/0 Not tainted
6.1.0-rc4-syzkaller-00159-g4bbf3422df78 #0
Hardware name: Google Compute Engine/Google Compute Engine, BIOS
Google 10/26/2022
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:151 [inline]
__ubsan_handle_shift_out_of_bounds+0x3a6/0x420 lib/ubsan.c:322
snto32 drivers/hid/hid-core.c:1323 [inline]
hid_input_fetch_field drivers/hid/hid-core.c:1572 [inline]
hid_process_report drivers/hid/hid-core.c:1665 [inline]
hid_report_raw_event+0xd56/0x18b0 drivers/hid/hid-core.c:1998
hid_input_report+0x408/0x4f0 drivers/hid/hid-core.c:2066
hid_irq_in+0x459/0x690 drivers/hid/usbhid/hid-core.c:284
__usb_hcd_giveback_urb+0x369/0x530 drivers/usb/core/hcd.c:1671
dummy_timer+0x86b/0x3110 drivers/usb/gadget/udc/dummy_hcd.c:1988
call_timer_fn+0xf5/0x210 kernel/time/timer.c:1474
expire_timers kernel/time/timer.c:1519 [inline]
__run_timers+0x76a/0x980 kernel/time/timer.c:1790
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803
__do_softirq+0x277/0x75b kernel/softirq.c:571
__irq_exit_rcu+0xec/0x170 kernel/softirq.c:650
irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1107
======================================================================
If the size of the integer (unsigned n) is bigger than 32 in snto32(),
shift exponent will be too large for 32-bit type 'int', resulting in a
shift-out-of-bounds bug.
Fix this by adding a check on the size of the integer (unsigned n) in
snto32(). To add support for n greater than 32 bits, set n to 32, if n
is greater than 32.