In the Linux kernel, the following vulnerability has been resolved:
arm64: kexec: initialize kexec_buf struct in load_other_segments()
Patch series "kexec: Fix invalid field access".
The kexec_buf structure was previo...Show moreIn the Linux kernel, the following vulnerability has been resolved:
arm64: kexec: initialize kexec_buf struct in load_other_segments()
Patch series "kexec: Fix invalid field access".
The kexec_buf structure was previously declared without initialization.
commit bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
added a field that is always read but not consistently populated by all
architectures. This un-initialized field will contain garbage.
This is also triggering a UBSAN warning when the uninitialized data was
accessed:
------------[ cut here ]------------
UBSAN: invalid-load in ./include/linux/kexec.h:210:10
load of value 252 is not a valid value for type '_Bool'
Zero-initializing kexec_buf at declaration ensures all fields are cleanly
set, preventing future instances of uninitialized memory being used.
An initial fix was already landed for arm64[0], and this patchset fixes
the problem on the remaining arm64 code and on riscv, as raised by Mark.
Discussions about this problem could be found at[1][2].
This patch (of 3):
The kexec_buf structure was previously declared without initialization.
commit bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
added a field that is always read but not consistently populated by all
architectures. This un-initialized field will contain garbage.
This is also triggering a UBSAN warning when the uninitialized data was
accessed:
------------[ cut here ]------------
UBSAN: invalid-load in ./include/linux/kexec.h:210:10
load of value 252 is not a valid value for type '_Bool'
Zero-initializing kexec_buf at declaration ensures all fields are
cleanly set, preventing future instances of uninitialized memory being
used.Show less |
In the Linux kernel, the following vulnerability has been resolved:
drm/sched: Check scheduler work queue before calling timeout handling
During an IGT GPU reset test we see again oops despite of
commit 0c8c901aaaebc9...Show moreIn the Linux kernel, the following vulnerability has been resolved:
drm/sched: Check scheduler work queue before calling timeout handling
During an IGT GPU reset test we see again oops despite of
commit 0c8c901aaaebc9 (drm/sched: Check scheduler ready before calling
timeout handling).
It uses ready condition whether to call drm_sched_fault which unwind
the TDR leads to GPU reset.
However it looks the ready condition is overloaded with other meanings,
for example, for the following stack is related GPU reset :
0 gfx_v9_0_cp_gfx_start
1 gfx_v9_0_cp_gfx_resume
2 gfx_v9_0_cp_resume
3 gfx_v9_0_hw_init
4 gfx_v9_0_resume
5 amdgpu_device_ip_resume_phase2
does the following:
/* start the ring */
gfx_v9_0_cp_gfx_start(adev);
ring->sched.ready = true;
The same approach is for other ASICs as well :
gfx_v8_0_cp_gfx_resume
gfx_v10_0_kiq_resume, etc...
As a result, our GPU reset test causes GPU fault which calls unconditionally gfx_v9_0_fault
and then drm_sched_fault. However now it depends on whether the interrupt service routine
drm_sched_fault is executed after gfx_v9_0_cp_gfx_start is completed which sets the ready
field of the scheduler to true even for uninitialized schedulers and causes oops vs
no fault or when ISR drm_sched_fault is completed prior gfx_v9_0_cp_gfx_start and
NULL pointer dereference does not occur.
Use the field timeout_wq to prevent oops for uninitialized schedulers.
The field could be initialized by the work queue of resetting the domain.
v1: Corrections to commit message (Luben)Show less |
In the Linux kernel, the following vulnerability has been resolved:
can: bcm: bcm_tx_setup(): fix KMSAN uninit-value in vfs_write
Syzkaller reported the following issue:
===============================================...Show moreIn the Linux kernel, the following vulnerability has been resolved:
can: bcm: bcm_tx_setup(): fix KMSAN uninit-value in vfs_write
Syzkaller reported the following issue:
=====================================================
BUG: KMSAN: uninit-value in aio_rw_done fs/aio.c:1520 [inline]
BUG: KMSAN: uninit-value in aio_write+0x899/0x950 fs/aio.c:1600
aio_rw_done fs/aio.c:1520 [inline]
aio_write+0x899/0x950 fs/aio.c:1600
io_submit_one+0x1d1c/0x3bf0 fs/aio.c:2019
__do_sys_io_submit fs/aio.c:2078 [inline]
__se_sys_io_submit+0x293/0x770 fs/aio.c:2048
__x64_sys_io_submit+0x92/0xd0 fs/aio.c:2048
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
Uninit was created at:
slab_post_alloc_hook mm/slab.h:766 [inline]
slab_alloc_node mm/slub.c:3452 [inline]
__kmem_cache_alloc_node+0x71f/0xce0 mm/slub.c:3491
__do_kmalloc_node mm/slab_common.c:967 [inline]
__kmalloc+0x11d/0x3b0 mm/slab_common.c:981
kmalloc_array include/linux/slab.h:636 [inline]
bcm_tx_setup+0x80e/0x29d0 net/can/bcm.c:930
bcm_sendmsg+0x3a2/0xce0 net/can/bcm.c:1351
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg net/socket.c:734 [inline]
sock_write_iter+0x495/0x5e0 net/socket.c:1108
call_write_iter include/linux/fs.h:2189 [inline]
aio_write+0x63a/0x950 fs/aio.c:1600
io_submit_one+0x1d1c/0x3bf0 fs/aio.c:2019
__do_sys_io_submit fs/aio.c:2078 [inline]
__se_sys_io_submit+0x293/0x770 fs/aio.c:2048
__x64_sys_io_submit+0x92/0xd0 fs/aio.c:2048
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
CPU: 1 PID: 5034 Comm: syz-executor350 Not tainted 6.2.0-rc6-syzkaller-80422-geda666ff2276 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
=====================================================
We can follow the call chain and find that 'bcm_tx_setup' function
calls 'memcpy_from_msg' to copy some content to the newly allocated
frame of 'op->frames'. After that the 'len' field of copied structure
being compared with some constant value (64 or 8). However, if
'memcpy_from_msg' returns an error, we will compare some uninitialized
memory. This triggers 'uninit-value' issue.
This patch will add 'memcpy_from_msg' possible errors processing to
avoid uninit-value issue.
Tested via syzkallerShow less |
In the Linux kernel, the following vulnerability has been resolved:
of/fdt: run soc memory setup when early_init_dt_scan_memory fails
If memory has been found early_init_dt_scan_memory now returns 1. If
it hasn't found...Show moreIn the Linux kernel, the following vulnerability has been resolved:
of/fdt: run soc memory setup when early_init_dt_scan_memory fails
If memory has been found early_init_dt_scan_memory now returns 1. If
it hasn't found any memory it will return 0, allowing other memory
setup mechanisms to carry on.
Previously early_init_dt_scan_memory always returned 0 without
distinguishing between any kind of memory setup being done or not. Any
code path after the early_init_dt_scan memory call in the ramips
plat_mem_setup code wouldn't be executed anymore. Making
early_init_dt_scan_memory the only way to initialize the memory.
Some boards, including my mt7621 based Cudy X6 board, depend on memory
initialization being done via the soc_info.mem_detect function
pointer. Those wouldn't be able to obtain memory and panic the kernel
during early bootup with the message "early_init_dt_alloc_memory_arch:
Failed to allocate 12416 bytes align=0x40".Show less |
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_{ldisc,serdev}: check percpu_init_rwsem() failure
syzbot is reporting NULL pointer dereference at hci_uart_tty_close() [1],
for rcu_syn...Show moreIn the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_{ldisc,serdev}: check percpu_init_rwsem() failure
syzbot is reporting NULL pointer dereference at hci_uart_tty_close() [1],
for rcu_sync_enter() is called without rcu_sync_init() due to
hci_uart_tty_open() ignoring percpu_init_rwsem() failure.
While we are at it, fix that hci_uart_register_device() ignores
percpu_init_rwsem() failure and hci_uart_unregister_device() does not
call percpu_free_rwsem().Show less |
In the Linux kernel, the following vulnerability has been resolved:
ext4: init quota for 'old.inode' in 'ext4_rename'
Syzbot found the following issue:
ext4_parse_param: s_want_extra_isize=128
ext4_inode_info_init: s_w...Show moreIn the Linux kernel, the following vulnerability has been resolved:
ext4: init quota for 'old.inode' in 'ext4_rename'
Syzbot found the following issue:
ext4_parse_param: s_want_extra_isize=128
ext4_inode_info_init: s_want_extra_isize=32
ext4_rename: old.inode=ffff88823869a2c8 old.dir=ffff888238699828 new.inode=ffff88823869d7e8 new.dir=ffff888238699828
__ext4_mark_inode_dirty: inode=ffff888238699828 ea_isize=32 want_ea_size=128
__ext4_mark_inode_dirty: inode=ffff88823869a2c8 ea_isize=32 want_ea_size=128
ext4_xattr_block_set: inode=ffff88823869a2c8
------------[ cut here ]------------
WARNING: CPU: 13 PID: 2234 at fs/ext4/xattr.c:2070 ext4_xattr_block_set.cold+0x22/0x980
Modules linked in:
RIP: 0010:ext4_xattr_block_set.cold+0x22/0x980
RSP: 0018:ffff888227d3f3b0 EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffff88823007a000 RCX: 0000000000000000
RDX: 0000000000000a03 RSI: 0000000000000040 RDI: ffff888230078178
RBP: 0000000000000000 R08: 000000000000002c R09: ffffed1075c7df8e
R10: ffff8883ae3efc6b R11: ffffed1075c7df8d R12: 0000000000000000
R13: ffff88823869a2c8 R14: ffff8881012e0460 R15: dffffc0000000000
FS: 00007f350ac1f740(0000) GS:ffff8883ae200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f350a6ed6a0 CR3: 0000000237456000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
? ext4_xattr_set_entry+0x3b7/0x2320
? ext4_xattr_block_set+0x0/0x2020
? ext4_xattr_set_entry+0x0/0x2320
? ext4_xattr_check_entries+0x77/0x310
? ext4_xattr_ibody_set+0x23b/0x340
ext4_xattr_move_to_block+0x594/0x720
ext4_expand_extra_isize_ea+0x59a/0x10f0
__ext4_expand_extra_isize+0x278/0x3f0
__ext4_mark_inode_dirty.cold+0x347/0x410
ext4_rename+0xed3/0x174f
vfs_rename+0x13a7/0x2510
do_renameat2+0x55d/0x920
__x64_sys_rename+0x7d/0xb0
do_syscall_64+0x3b/0xa0
entry_SYSCALL_64_after_hwframe+0x72/0xdc
As 'ext4_rename' will modify 'old.inode' ctime and mark inode dirty,
which may trigger expand 'extra_isize' and allocate block. If inode
didn't init quota will lead to warning. To solve above issue, init
'old.inode' firstly in 'ext4_rename'.Show less |
In the Linux kernel, the following vulnerability has been resolved:
mISDN: hfcpci: Fix warning when deleting uninitialized timer
With CONFIG_DEBUG_OBJECTS_TIMERS unloading hfcpci module leads
to the following splat:
[...Show moreIn the Linux kernel, the following vulnerability has been resolved:
mISDN: hfcpci: Fix warning when deleting uninitialized timer
With CONFIG_DEBUG_OBJECTS_TIMERS unloading hfcpci module leads
to the following splat:
[ 250.215892] ODEBUG: assert_init not available (active state 0) object: ffffffffc01a3dc0 object type: timer_list hint: 0x0
[ 250.217520] WARNING: CPU: 0 PID: 233 at lib/debugobjects.c:612 debug_print_object+0x1b6/0x2c0
[ 250.218775] Modules linked in: hfcpci(-) mISDN_core
[ 250.219537] CPU: 0 UID: 0 PID: 233 Comm: rmmod Not tainted 6.17.0-rc2-g6f713187ac98 #2 PREEMPT(voluntary)
[ 250.220940] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 250.222377] RIP: 0010:debug_print_object+0x1b6/0x2c0
[ 250.223131] Code: fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 4f 41 56 48 8b 14 dd a0 4e 01 9f 48 89 ee 48 c7 c7 20 46 01 9f e8 cb 84d
[ 250.225805] RSP: 0018:ffff888015ea7c08 EFLAGS: 00010286
[ 250.226608] RAX: 0000000000000000 RBX: 0000000000000005 RCX: ffffffff9be93a95
[ 250.227708] RDX: 1ffff1100d945138 RSI: 0000000000000008 RDI: ffff88806ca289c0
[ 250.228993] RBP: ffffffff9f014a00 R08: 0000000000000001 R09: ffffed1002bd4f39
[ 250.230043] R10: ffff888015ea79cf R11: 0000000000000001 R12: 0000000000000001
[ 250.231185] R13: ffffffff9eea0520 R14: 0000000000000000 R15: ffff888015ea7cc8
[ 250.232454] FS: 00007f3208f01540(0000) GS:ffff8880caf5a000(0000) knlGS:0000000000000000
[ 250.233851] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 250.234856] CR2: 00007f32090a7421 CR3: 0000000004d63000 CR4: 00000000000006f0
[ 250.236117] Call Trace:
[ 250.236599] <TASK>
[ 250.236967] ? trace_irq_enable.constprop.0+0xd4/0x130
[ 250.237920] debug_object_assert_init+0x1f6/0x310
[ 250.238762] ? __pfx_debug_object_assert_init+0x10/0x10
[ 250.239658] ? __lock_acquire+0xdea/0x1c70
[ 250.240369] __try_to_del_timer_sync+0x69/0x140
[ 250.241172] ? __pfx___try_to_del_timer_sync+0x10/0x10
[ 250.242058] ? __timer_delete_sync+0xc6/0x120
[ 250.242842] ? lock_acquire+0x30/0x80
[ 250.243474] ? __timer_delete_sync+0xc6/0x120
[ 250.244262] __timer_delete_sync+0x98/0x120
[ 250.245015] HFC_cleanup+0x10/0x20 [hfcpci]
[ 250.245704] __do_sys_delete_module+0x348/0x510
[ 250.246461] ? __pfx___do_sys_delete_module+0x10/0x10
[ 250.247338] do_syscall_64+0xc1/0x360
[ 250.247924] entry_SYSCALL_64_after_hwframe+0x77/0x7f
Fix this by initializing hfc_tl timer with DEFINE_TIMER macro.
Also, use mod_timer instead of manual timeout update.Show less |
In the Linux kernel, the following vulnerability has been resolved:
sctp: initialize more fields in sctp_v6_from_sk()
syzbot found that sin6_scope_id was not properly initialized,
leading to undefined behavior.
Clear...Show moreIn the Linux kernel, the following vulnerability has been resolved:
sctp: initialize more fields in sctp_v6_from_sk()
syzbot found that sin6_scope_id was not properly initialized,
leading to undefined behavior.
Clear sin6_scope_id and sin6_flowinfo.
BUG: KMSAN: uninit-value in __sctp_v6_cmp_addr+0x887/0x8c0 net/sctp/ipv6.c:649
__sctp_v6_cmp_addr+0x887/0x8c0 net/sctp/ipv6.c:649
sctp_inet6_cmp_addr+0x4f2/0x510 net/sctp/ipv6.c:983
sctp_bind_addr_conflict+0x22a/0x3b0 net/sctp/bind_addr.c:390
sctp_get_port_local+0x21eb/0x2440 net/sctp/socket.c:8452
sctp_get_port net/sctp/socket.c:8523 [inline]
sctp_listen_start net/sctp/socket.c:8567 [inline]
sctp_inet_listen+0x710/0xfd0 net/sctp/socket.c:8636
__sys_listen_socket net/socket.c:1912 [inline]
__sys_listen net/socket.c:1927 [inline]
__do_sys_listen net/socket.c:1932 [inline]
__se_sys_listen net/socket.c:1930 [inline]
__x64_sys_listen+0x343/0x4c0 net/socket.c:1930
x64_sys_call+0x271d/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:51
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Local variable addr.i.i created at:
sctp_get_port net/sctp/socket.c:8515 [inline]
sctp_listen_start net/sctp/socket.c:8567 [inline]
sctp_inet_listen+0x650/0xfd0 net/sctp/socket.c:8636
__sys_listen_socket net/socket.c:1912 [inline]
__sys_listen net/socket.c:1927 [inline]
__do_sys_listen net/socket.c:1932 [inline]
__se_sys_listen net/socket.c:1930 [inline]
__x64_sys_listen+0x343/0x4c0 net/socket.c:1930Show less |
In the Linux kernel, the following vulnerability has been resolved:
9p: set req refcount to zero to avoid uninitialized usage
When a new request is allocated, the refcount will be zero if it is
reused, but if the reque...Show moreIn the Linux kernel, the following vulnerability has been resolved:
9p: set req refcount to zero to avoid uninitialized usage
When a new request is allocated, the refcount will be zero if it is
reused, but if the request is newly allocated from slab, it is not fully
initialized before being added to idr.
If the p9_read_work got a response before the refcount initiated. It will
use a uninitialized req, which will result in a bad request data struct.
Here is the logs from syzbot.
Corrupted memory at 0xffff88807eade00b [ 0xff 0x07 0x00 0x00 0x00 0x00
0x00 0x00 . . . . . . . . ] (in kfence-#110):
p9_fcall_fini net/9p/client.c:248 [inline]
p9_req_put net/9p/client.c:396 [inline]
p9_req_put+0x208/0x250 net/9p/client.c:390
p9_client_walk+0x247/0x540 net/9p/client.c:1165
clone_fid fs/9p/fid.h:21 [inline]
v9fs_fid_xattr_set+0xe4/0x2b0 fs/9p/xattr.c:118
v9fs_xattr_set fs/9p/xattr.c:100 [inline]
v9fs_xattr_handler_set+0x6f/0x120 fs/9p/xattr.c:159
__vfs_setxattr+0x119/0x180 fs/xattr.c:182
__vfs_setxattr_noperm+0x129/0x5f0 fs/xattr.c:216
__vfs_setxattr_locked+0x1d3/0x260 fs/xattr.c:277
vfs_setxattr+0x143/0x340 fs/xattr.c:309
setxattr+0x146/0x160 fs/xattr.c:617
path_setxattr+0x197/0x1c0 fs/xattr.c:636
__do_sys_setxattr fs/xattr.c:652 [inline]
__se_sys_setxattr fs/xattr.c:648 [inline]
__ia32_sys_setxattr+0xc0/0x160 fs/xattr.c:648
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
entry_SYSENTER_compat_after_hwframe+0x70/0x82
Below is a similar scenario, the scenario in the syzbot log looks more
complicated than this one, but this patch can fix it.
T21124 p9_read_work
======================== second trans =================================
p9_client_walk
p9_client_rpc
p9_client_prepare_req
p9_tag_alloc
req = kmem_cache_alloc(p9_req_cache, GFP_NOFS);
tag = idr_alloc
<< preempted >>
req->tc.tag = tag;
/* req->[refcount/tag] == uninitialized */
m->rreq = p9_tag_lookup(m->client, m->rc.tag);
/* increments uninitalized refcount */
refcount_set(&req->refcount, 2);
/* cb drops one ref */
p9_client_cb(req)
/* reader thread drops its ref:
request is incorrectly freed */
p9_req_put(req)
/* use after free and ref underflow */
p9_req_put(req)
To fix it, we can initialize the refcount to zero before add to idr.Show less |
In the Linux kernel, the following vulnerability has been resolved:
chardev: fix error handling in cdev_device_add()
While doing fault injection test, I got the following report:
------------[ cut here ]------------
k...Show moreIn the Linux kernel, the following vulnerability has been resolved:
chardev: fix error handling in cdev_device_add()
While doing fault injection test, I got the following report:
------------[ cut here ]------------
kobject: '(null)' (0000000039956980): is not initialized, yet kobject_put() is being called.
WARNING: CPU: 3 PID: 6306 at kobject_put+0x23d/0x4e0
CPU: 3 PID: 6306 Comm: 283 Tainted: G W 6.1.0-rc2-00005-g307c1086d7c9 #1253
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:kobject_put+0x23d/0x4e0
Call Trace:
<TASK>
cdev_device_add+0x15e/0x1b0
__iio_device_register+0x13b4/0x1af0 [industrialio]
__devm_iio_device_register+0x22/0x90 [industrialio]
max517_probe+0x3d8/0x6b4 [max517]
i2c_device_probe+0xa81/0xc00
When device_add() is injected fault and returns error, if dev->devt is not set,
cdev_add() is not called, cdev_del() is not needed. Fix this by checking dev->devt
in error path.Show less |
In the Linux kernel, the following vulnerability has been resolved:
udf: Fix uninitialized array access for some pathnames
For filenames that begin with . and are between 2 and 5 characters long,
UDF charset conversion...Show moreIn the Linux kernel, the following vulnerability has been resolved:
udf: Fix uninitialized array access for some pathnames
For filenames that begin with . and are between 2 and 5 characters long,
UDF charset conversion code would read uninitialized memory in the
output buffer. The only practical impact is that the name may be prepended a
"unification hash" when it is not actually needed but still it is good
to fix this.Show less |
In the Linux kernel, the following vulnerability has been resolved:
iommu/mediatek: Fix crash on isr after kexec()
If the system is rebooted via isr(), the IRQ handler might
be triggered before the domain is initialize...Show moreIn the Linux kernel, the following vulnerability has been resolved:
iommu/mediatek: Fix crash on isr after kexec()
If the system is rebooted via isr(), the IRQ handler might
be triggered before the domain is initialized. Resulting on
an invalid memory access error.
Fix:
[ 0.500930] Unable to handle kernel read from unreadable memory at virtual address 0000000000000070
[ 0.501166] Call trace:
[ 0.501174] report_iommu_fault+0x28/0xfc
[ 0.501180] mtk_iommu_isr+0x10c/0x1c0
[ joro: Fixed spelling in commit message ]Show less |
Use of uninitialized resource in Windows Imaging Component allows an unauthorized attacker to disclose information locally. |
In the Linux kernel, the following vulnerability has been resolved:
iio: accel: sca3300: fix uninitialized iio scan data
Fix potential leak of uninitialized stack data to userspace by ensuring
that the `channels` array...Show moreIn the Linux kernel, the following vulnerability has been resolved:
iio: accel: sca3300: fix uninitialized iio scan data
Fix potential leak of uninitialized stack data to userspace by ensuring
that the `channels` array is zeroed before use.Show less |
In the Linux kernel, the following vulnerability has been resolved:
comedi: Fix use of uninitialized memory in do_insn_ioctl() and do_insnlist_ioctl()
syzbot reports a KMSAN kernel-infoleak in `do_insn_ioctl()`. A ker...Show moreIn the Linux kernel, the following vulnerability has been resolved:
comedi: Fix use of uninitialized memory in do_insn_ioctl() and do_insnlist_ioctl()
syzbot reports a KMSAN kernel-infoleak in `do_insn_ioctl()`. A kernel
buffer is allocated to hold `insn->n` samples (each of which is an
`unsigned int`). For some instruction types, `insn->n` samples are
copied back to user-space, unless an error code is being returned. The
problem is that not all the instruction handlers that need to return
data to userspace fill in the whole `insn->n` samples, so that there is
an information leak. There is a similar syzbot report for
`do_insnlist_ioctl()`, although it does not have a reproducer for it at
the time of writing.
One culprit is `insn_rw_emulate_bits()` which is used as the handler for
`INSN_READ` or `INSN_WRITE` instructions for subdevices that do not have
a specific handler for that instruction, but do have an `INSN_BITS`
handler. For `INSN_READ` it only fills in at most 1 sample, so if
`insn->n` is greater than 1, the remaining `insn->n - 1` samples copied
to userspace will be uninitialized kernel data.
Another culprit is `vm80xx_ai_insn_read()` in the "vm80xx" driver. It
never returns an error, even if it fails to fill the buffer.
Fix it in `do_insn_ioctl()` and `do_insnlist_ioctl()` by making sure
that uninitialized parts of the allocated buffer are zeroed before
handling each instruction.
Thanks to Arnaud Lecomte for their fix to `do_insn_ioctl()`. That fix
replaced the call to `kmalloc_array()` with `kcalloc()`, but it is not
always necessary to clear the whole buffer.Show less |
In the Linux kernel, the following vulnerability has been resolved:
cifs: Fix oops due to uninitialised variable
Fix smb3_init_transform_rq() to initialise buffer to NULL before calling
netfs_alloc_folioq_buffer() as n...Show moreIn the Linux kernel, the following vulnerability has been resolved:
cifs: Fix oops due to uninitialised variable
Fix smb3_init_transform_rq() to initialise buffer to NULL before calling
netfs_alloc_folioq_buffer() as netfs assumes it can append to the buffer it
is given. Setting it to NULL means it should start a fresh buffer, but the
value is currently undefined.Show less |
In the Linux kernel, the following vulnerability has been resolved:
sctp: linearize cloned gso packets in sctp_rcv
A cloned head skb still shares these frag skbs in fraglist with the
original head skb. It's not safe to...Show moreIn the Linux kernel, the following vulnerability has been resolved:
sctp: linearize cloned gso packets in sctp_rcv
A cloned head skb still shares these frag skbs in fraglist with the
original head skb. It's not safe to access these frag skbs.
syzbot reported two use-of-uninitialized-memory bugs caused by this:
BUG: KMSAN: uninit-value in sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211
sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211
sctp_assoc_bh_rcv+0x1a7/0xc50 net/sctp/associola.c:998
sctp_inq_push+0x2ef/0x380 net/sctp/inqueue.c:88
sctp_backlog_rcv+0x397/0xdb0 net/sctp/input.c:331
sk_backlog_rcv+0x13b/0x420 include/net/sock.h:1122
__release_sock+0x1da/0x330 net/core/sock.c:3106
release_sock+0x6b/0x250 net/core/sock.c:3660
sctp_wait_for_connect+0x487/0x820 net/sctp/socket.c:9360
sctp_sendmsg_to_asoc+0x1ec1/0x1f00 net/sctp/socket.c:1885
sctp_sendmsg+0x32b9/0x4a80 net/sctp/socket.c:2031
inet_sendmsg+0x25a/0x280 net/ipv4/af_inet.c:851
sock_sendmsg_nosec net/socket.c:718 [inline]
and
BUG: KMSAN: uninit-value in sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987
sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987
sctp_inq_push+0x2a3/0x350 net/sctp/inqueue.c:88
sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331
sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148
__release_sock+0x1d3/0x330 net/core/sock.c:3213
release_sock+0x6b/0x270 net/core/sock.c:3767
sctp_wait_for_connect+0x458/0x820 net/sctp/socket.c:9367
sctp_sendmsg_to_asoc+0x223a/0x2260 net/sctp/socket.c:1886
sctp_sendmsg+0x3910/0x49f0 net/sctp/socket.c:2032
inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851
sock_sendmsg_nosec net/socket.c:712 [inline]
This patch fixes it by linearizing cloned gso packets in sctp_rcv().Show less |
In the Linux kernel, the following vulnerability has been resolved:
pNFS: Fix uninited ptr deref in block/scsi layout
The error occurs on the third attempt to encode extents. When function
ext_tree_prepare_commit() rea...Show moreIn the Linux kernel, the following vulnerability has been resolved:
pNFS: Fix uninited ptr deref in block/scsi layout
The error occurs on the third attempt to encode extents. When function
ext_tree_prepare_commit() reallocates a larger buffer to retry encoding
extents, the "layoutupdate_pages" page array is initialized only after the
retry loop. But ext_tree_free_commitdata() is called on every iteration
and tries to put pages in the array, thus dereferencing uninitialized
pointers.
An additional problem is that there is no limit on the maximum possible
buffer_size. When there are too many extents, the client may create a
layoutcommit that is larger than the maximum possible RPC size accepted
by the server.
During testing, we observed two typical scenarios. First, one memory page
for extents is enough when we work with small files, append data to the
end of the file, or preallocate extents before writing. But when we fill
a new large file without preallocating, the number of extents can be huge,
and counting the number of written extents in ext_tree_encode_commit()
does not help much. Since this number increases even more between
unlocking and locking of ext_tree, the reallocated buffer may not be
large enough again and again.Show less |
In ReadTachyonCommands of gxp_main_actor.cc, there is a possible information leak due to uninitialized data. This could lead to local information disclosure with no additional execution privileges needed. User interactio...Show moreIn ReadTachyonCommands of gxp_main_actor.cc, there is a possible information leak due to uninitialized data. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.Show less |
In the Linux kernel, the following vulnerability has been resolved:
nvmet: pci-epf: Do not complete commands twice if nvmet_req_init() fails
Have nvmet_req_init() and req->execute() complete failed commands.
Descripti...Show moreIn the Linux kernel, the following vulnerability has been resolved:
nvmet: pci-epf: Do not complete commands twice if nvmet_req_init() fails
Have nvmet_req_init() and req->execute() complete failed commands.
Description of the problem:
nvmet_req_init() calls __nvmet_req_complete() internally upon failure,
e.g., unsupported opcode, which calls the "queue_response" callback,
this results in nvmet_pci_epf_queue_response() being called, which will
call nvmet_pci_epf_complete_iod() if data_len is 0 or if dma_dir is
different from DMA_TO_DEVICE. This results in a double completion as
nvmet_pci_epf_exec_iod_work() also calls nvmet_pci_epf_complete_iod()
when nvmet_req_init() fails.
Steps to reproduce:
On the host send a command with an unsupported opcode with nvme-cli,
For example the admin command "security receive"
$ sudo nvme security-recv /dev/nvme0n1 -n1 -x4096
This triggers a double completion as nvmet_req_init() fails and
nvmet_pci_epf_queue_response() is called, here iod->dma_dir is still
in the default state of "DMA_NONE" as set by default in
nvmet_pci_epf_alloc_iod(), so nvmet_pci_epf_complete_iod() is called.
Because nvmet_req_init() failed nvmet_pci_epf_complete_iod() is also
called in nvmet_pci_epf_exec_iod_work() leading to a double completion.
This not only sends two completions to the host but also corrupts the
state of the PCI NVMe target leading to kernel oops.
This patch lets nvmet_req_init() and req->execute() complete all failed
commands, and removes the double completion case in
nvmet_pci_epf_exec_iod_work() therefore fixing the edge cases where
double completions occurred.Show less |