In the Linux kernel, the following vulnerability has been resolved:
KVM: s390/diag: fix racy access of physical cpu number in diag 9c handler
We do check for target CPU == -1, but this might change at the time we
are going to use it. Hold the physical target CPU in a local variable to
avoid out-of-bound accesses to the cpu arrays.
In the Linux kernel, the following vulnerability has been resolved:
block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq
Commit 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'")
will access 'bic->bfqq' in bic_set_bfqq(), however, bfq_exit_icq_bfqq()
can free bfqq first, and then call bic_set_bfqq(), which will cause uaf.
Fix the problem by moving bfq_exit_bfqq() behind bic_set_bfqq().
In the Linux kernel, the following vulnerability has been resolved:
crypto: cavium - prevent integer overflow loading firmware
The "code_length" value comes from the firmware file. If your firmware
is untrusted realistically there is probably very little you can do to
protect yourself. Still we try to limit the damage as much as possible.
Also Smatch marks any data read from the filesystem as untrusted and
prints warnings if it not capped correctly.
The "ntohl(ucode->code_length) * 2" multiplication can have an
integer overflow.
In the Linux kernel, the following vulnerability has been resolved:
wwan_hwsim: fix possible memory leak in wwan_hwsim_dev_new()
Inject fault while probing module, if device_register() fails,
but the refcount of kobject is not decreased to 0, the name
allocated in dev_set_name() is leaked. Fix this by calling
put_device(), so that name can be freed in callback function
kobject_cleanup().
unreferenced object 0xffff88810152ad20 (size 8):
comm "modprobe", pid 252, jiffies 4294849206 (age 22.713s)
hex dump (first 8 bytes):
68 77 73 69 6d 30 00 ff hwsim0..
backtrace:
[<000000009c3504ed>] __kmalloc_node_track_caller+0x44/0x1b0
[<00000000c0228a5e>] kvasprintf+0xb5/0x140
[<00000000cff8c21f>] kvasprintf_const+0x55/0x180
[<0000000055a1e073>] kobject_set_name_vargs+0x56/0x150
[<000000000a80b139>] dev_set_name+0xab/0xe0
In the Linux kernel, the following vulnerability has been resolved:
video/aperture: Call sysfb_disable() before removing PCI devices
Call sysfb_disable() from aperture_remove_conflicting_pci_devices()
before removing PCI devices. Without, simpledrm can still bind to
simple-framebuffer devices after the hardware driver has taken over
the hardware. Both drivers interfere with each other and results are
undefined.
Reported modesetting errors [1] are shown below.
---- snap ----
rcu: INFO: rcu_sched detected expedited stalls on CPUs/tasks: { 13-.... } 7 jiffies s: 165 root: 0x2000/.
rcu: blocking rcu_node structures (internal RCU debug):
Task dump for CPU 13:
task:X state:R running task stack: 0 pid: 4242 ppid: 4228 flags:0x00000008
Call Trace:
<TASK>
? commit_tail+0xd7/0x130
? drm_atomic_helper_commit+0x126/0x150
? drm_atomic_commit+0xa4/0xe0
? drm_plane_get_damage_clips.cold+0x1c/0x1c
? drm_atomic_helper_dirtyfb+0x19e/0x280
? drm_mode_dirtyfb_ioctl+0x10f/0x1e0
? drm_mode_getfb2_ioctl+0x2d0/0x2d0
? drm_ioctl_kernel+0xc4/0x150
? drm_ioctl+0x246/0x3f0
? drm_mode_getfb2_ioctl+0x2d0/0x2d0
? __x64_sys_ioctl+0x91/0xd0
? do_syscall_64+0x60/0xd0
? entry_SYSCALL_64_after_hwframe+0x4b/0xb5
</TASK>
...
rcu: INFO: rcu_sched detected expedited stalls on CPUs/tasks: { 13-.... } 30 jiffies s: 169 root: 0x2000/.
rcu: blocking rcu_node structures (internal RCU debug):
Task dump for CPU 13:
task:X state:R running task stack: 0 pid: 4242 ppid: 4228 flags:0x0000400e
Call Trace:
<TASK>
? memcpy_toio+0x76/0xc0
? memcpy_toio+0x1b/0xc0
? drm_fb_memcpy_toio+0x76/0xb0
? drm_fb_blit_toio+0x75/0x2b0
? simpledrm_simple_display_pipe_update+0x132/0x150
? drm_atomic_helper_commit_planes+0xb6/0x230
? drm_atomic_helper_commit_tail+0x44/0x80
? commit_tail+0xd7/0x130
? drm_atomic_helper_commit+0x126/0x150
? drm_atomic_commit+0xa4/0xe0
? drm_plane_get_damage_clips.cold+0x1c/0x1c
? drm_atomic_helper_dirtyfb+0x19e/0x280
? drm_mode_dirtyfb_ioctl+0x10f/0x1e0
? drm_mode_getfb2_ioctl+0x2d0/0x2d0
? drm_ioctl_kernel+0xc4/0x150
? drm_ioctl+0x246/0x3f0
? drm_mode_getfb2_ioctl+0x2d0/0x2d0
? __x64_sys_ioctl+0x91/0xd0
? do_syscall_64+0x60/0xd0
? entry_SYSCALL_64_after_hwframe+0x4b/0xb5
</TASK>
The problem was added by commit 5e0137612430 ("video/aperture: Disable
and unregister sysfb devices via aperture helpers") to v6.0.3 and does
not exist in the mainline branch.
The mainline commit 5e0137612430 ("video/aperture: Disable and
unregister sysfb devices via aperture helpers") has been backported
from v6.0-rc1 to stable v6.0.3 from a larger patch series [2] that
reworks fbdev framebuffer ownership. The backport misses a change to
aperture_remove_conflicting_pci_devices(). Mainline itself is fine,
because the function does not exist there as a result of the patch
series.
Instead of backporting the whole series, fix the additional function.
In the Linux kernel, the following vulnerability has been resolved:
fs: jfs: fix shift-out-of-bounds in dbDiscardAG
This should be applied to most URSAN bugs found recently by syzbot,
by guarding the dbMount. As syzbot feeding rubbish into the bmap
descriptor.
In the Linux kernel, the following vulnerability has been resolved:
hugetlbfs: fix null-ptr-deref in hugetlbfs_parse_param()
Syzkaller reports a null-ptr-deref bug as follows:
======================================================
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
RIP: 0010:hugetlbfs_parse_param+0x1dd/0x8e0 fs/hugetlbfs/inode.c:1380
[...]
Call Trace:
<TASK>
vfs_parse_fs_param fs/fs_context.c:148 [inline]
vfs_parse_fs_param+0x1f9/0x3c0 fs/fs_context.c:129
vfs_parse_fs_string+0xdb/0x170 fs/fs_context.c:191
generic_parse_monolithic+0x16f/0x1f0 fs/fs_context.c:231
do_new_mount fs/namespace.c:3036 [inline]
path_mount+0x12de/0x1e20 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
[...]
</TASK>
======================================================
According to commit "vfs: parse: deal with zero length string value",
kernel will set the param->string to null pointer in vfs_parse_fs_string()
if fs string has zero length.
Yet the problem is that, hugetlbfs_parse_param() will dereference the
param->string, without checking whether it is a null pointer. To be more
specific, if hugetlbfs_parse_param() parses an illegal mount parameter,
such as "size=,", kernel will constructs struct fs_parameter with null
pointer in vfs_parse_fs_string(), then passes this struct fs_parameter to
hugetlbfs_parse_param(), which triggers the above null-ptr-deref bug.
This patch solves it by adding sanity check on param->string
in hugetlbfs_parse_param().
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 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.
In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmfmac: fix potential memory leak in brcmf_netdev_start_xmit()
The brcmf_netdev_start_xmit() returns NETDEV_TX_OK without freeing skb
in case of pskb_expand_head() fails, add dev_kfree_skb() to fix it.
Compile tested only.