| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Acquire SRCU in KVM_GET_MP_STATE to protect guest memory accesses
Acquire a lock on kvm->srcu when userspace is getting MP state to handle a
rather extreme edge case where "accepting" APIC events, i.e. processing
pending INIT or SIPI, can trigger accesses to guest memory. If the vCPU
is in L2 with INIT *and* a TRIPLE_FAULT request pending, then getting MP
state will trigger a nested VM-Exit by way of ->check_nested_events(), and
emuating the nested VM-Exit can access guest memory.
The splat was originally hit by syzkaller on a Google-internal kernel, and
reproduced on an upstream kernel by hacking the triple_fault_event_test
selftest to stuff a pending INIT, store an MSR on VM-Exit (to generate a
memory access on VMX), and do vcpu_mp_state_get() to trigger the scenario.
=============================
WARNING: suspicious RCU usage
6.14.0-rc3-b112d356288b-vmx/pi_lockdep_false_pos-lock #3 Not tainted
-----------------------------
include/linux/kvm_host.h:1058 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by triple_fault_ev/1256:
#0: ffff88810df5a330 (&vcpu->mutex){+.+.}-{4:4}, at: kvm_vcpu_ioctl+0x8b/0x9a0 [kvm]
stack backtrace:
CPU: 11 UID: 1000 PID: 1256 Comm: triple_fault_ev Not tainted 6.14.0-rc3-b112d356288b-vmx #3
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Call Trace:
<TASK>
dump_stack_lvl+0x7f/0x90
lockdep_rcu_suspicious+0x144/0x190
kvm_vcpu_gfn_to_memslot+0x156/0x180 [kvm]
kvm_vcpu_read_guest+0x3e/0x90 [kvm]
read_and_check_msr_entry+0x2e/0x180 [kvm_intel]
__nested_vmx_vmexit+0x550/0xde0 [kvm_intel]
kvm_check_nested_events+0x1b/0x30 [kvm]
kvm_apic_accept_events+0x33/0x100 [kvm]
kvm_arch_vcpu_ioctl_get_mpstate+0x30/0x1d0 [kvm]
kvm_vcpu_ioctl+0x33e/0x9a0 [kvm]
__x64_sys_ioctl+0x8b/0xb0
do_syscall_64+0x6c/0x170
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK> |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix oob access in cgroup local storage
Lonial reported that an out-of-bounds access in cgroup local storage
can be crafted via tail calls. Given two programs each utilizing a
cgroup local storage with a different value size, and one program
doing a tail call into the other. The verifier will validate each of
the indivial programs just fine. However, in the runtime context
the bpf_cg_run_ctx holds an bpf_prog_array_item which contains the
BPF program as well as any cgroup local storage flavor the program
uses. Helpers such as bpf_get_local_storage() pick this up from the
runtime context:
ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx);
storage = ctx->prog_item->cgroup_storage[stype];
if (stype == BPF_CGROUP_STORAGE_SHARED)
ptr = &READ_ONCE(storage->buf)->data[0];
else
ptr = this_cpu_ptr(storage->percpu_buf);
For the second program which was called from the originally attached
one, this means bpf_get_local_storage() will pick up the former
program's map, not its own. With mismatching sizes, this can result
in an unintended out-of-bounds access.
To fix this issue, we need to extend bpf_map_owner with an array of
storage_cookie[] to match on i) the exact maps from the original
program if the second program was using bpf_get_local_storage(), or
ii) allow the tail call combination if the second program was not
using any of the cgroup local storage maps. |
| The client in OpenSSH before 7.2 mishandles failed cookie generation for untrusted X11 forwarding and relies on the local X11 server for access-control decisions, which allows remote X11 clients to trigger a fallback and obtain trusted X11 forwarding privileges by leveraging configuration issues on this X11 server, as demonstrated by lack of the SECURITY extension on this X11 server. |
| An issue was discovered in drivers/accessibility/speakup/spk_ttyio.c in the Linux kernel through 5.9.9. Local attackers on systems with the speakup driver could cause a local denial of service attack, aka CID-d41227544427. This occurs because of an invalid free when the line discipline is used more than once. |
| png_image_free in png.c in libpng 1.6.x before 1.6.37 has a use-after-free because png_image_free_function is called under png_safe_execute. |
| In xsltCopyText in transform.c in libxslt 1.1.33, a pointer variable isn't reset under certain circumstances. If the relevant memory area happened to be freed and reused in a certain way, a bounds check could fail and memory outside a buffer could be written to, or uninitialized data could be disclosed. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix index out of bounds in degamma hardware format translation
Fixes index out of bounds issue in
`cm_helper_translate_curve_to_degamma_hw_format` function. The issue
could occur when the index 'i' exceeds the number of transfer function
points (TRANSFER_FUNC_POINTS).
The fix adds a check to ensure 'i' is within bounds before accessing the
transfer function points. If 'i' is out of bounds the function returns
false to indicate an error.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:594 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.red' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:595 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.green' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:596 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.blue' 1025 <= s32max |
| In the Linux kernel, the following vulnerability has been resolved:
fbdev: pxafb: Fix possible use after free in pxafb_task()
In the pxafb_probe function, it calls the pxafb_init_fbinfo function,
after which &fbi->task is associated with pxafb_task. Moreover,
within this pxafb_init_fbinfo function, the pxafb_blank function
within the &pxafb_ops struct is capable of scheduling work.
If we remove the module which will call pxafb_remove to make cleanup,
it will call unregister_framebuffer function which can call
do_unregister_framebuffer to free fbi->fb through
put_fb_info(fb_info), while the work mentioned above will be used.
The sequence of operations that may lead to a UAF bug is as follows:
CPU0 CPU1
| pxafb_task
pxafb_remove |
unregister_framebuffer(info) |
do_unregister_framebuffer(fb_info) |
put_fb_info(fb_info) |
// free fbi->fb | set_ctrlr_state(fbi, state)
| __pxafb_lcd_power(fbi, 0)
| fbi->lcd_power(on, &fbi->fb.var)
| //use fbi->fb
Fix it by ensuring that the work is canceled before proceeding
with the cleanup in pxafb_remove.
Note that only root user can remove the driver at runtime. |
| The RC4 algorithm, as used in the TLS protocol and SSL protocol, does not properly combine state data with key data during the initialization phase, which makes it easier for remote attackers to conduct plaintext-recovery attacks against the initial bytes of a stream by sniffing network traffic that occasionally relies on keys affected by the Invariance Weakness, and then using a brute-force approach involving LSB values, aka the "Bar Mitzvah" issue. |
| The TLS protocol 1.2 and earlier, when a DHE_EXPORT ciphersuite is enabled on a server but not on a client, does not properly convey a DHE_EXPORT choice, which allows man-in-the-middle attackers to conduct cipher-downgrade attacks by rewriting a ClientHello with DHE replaced by DHE_EXPORT and then rewriting a ServerHello with DHE_EXPORT replaced by DHE, aka the "Logjam" issue. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: algif_aead - Revert to operating out-of-place
This mostly reverts commit 72548b093ee3 except for the copying of
the associated data.
There is no benefit in operating in-place in algif_aead since the
source and destination come from different mappings. Get rid of
all the complexity added for in-place operation and just copy the
AD directly. |
| A vulnerability was found in systemd-coredump. This flaw allows an attacker to force a SUID process to crash and replace it with a non-SUID binary to access the original's privileged process coredump, allowing the attacker to read sensitive data, such as /etc/shadow content, loaded by the original process.
A SUID binary or process has a special type of permission, which allows the process to run with the file owner's permissions, regardless of the user executing the binary. This allows the process to access more restricted data than unprivileged users or processes would be able to. An attacker can leverage this flaw by forcing a SUID process to crash and force the Linux kernel to recycle the process PID before systemd-coredump can analyze the /proc/pid/auxv file. If the attacker wins the race condition, they gain access to the original's SUID process coredump file. They can read sensitive content loaded into memory by the original binary, affecting data confidentiality. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: fix slab-use-after-free in ext4_split_extent_at()
We hit the following use-after-free:
==================================================================
BUG: KASAN: slab-use-after-free in ext4_split_extent_at+0xba8/0xcc0
Read of size 2 at addr ffff88810548ed08 by task kworker/u20:0/40
CPU: 0 PID: 40 Comm: kworker/u20:0 Not tainted 6.9.0-dirty #724
Call Trace:
<TASK>
kasan_report+0x93/0xc0
ext4_split_extent_at+0xba8/0xcc0
ext4_split_extent.isra.0+0x18f/0x500
ext4_split_convert_extents+0x275/0x750
ext4_ext_handle_unwritten_extents+0x73e/0x1580
ext4_ext_map_blocks+0xe20/0x2dc0
ext4_map_blocks+0x724/0x1700
ext4_do_writepages+0x12d6/0x2a70
[...]
Allocated by task 40:
__kmalloc_noprof+0x1ac/0x480
ext4_find_extent+0xf3b/0x1e70
ext4_ext_map_blocks+0x188/0x2dc0
ext4_map_blocks+0x724/0x1700
ext4_do_writepages+0x12d6/0x2a70
[...]
Freed by task 40:
kfree+0xf1/0x2b0
ext4_find_extent+0xa71/0x1e70
ext4_ext_insert_extent+0xa22/0x3260
ext4_split_extent_at+0x3ef/0xcc0
ext4_split_extent.isra.0+0x18f/0x500
ext4_split_convert_extents+0x275/0x750
ext4_ext_handle_unwritten_extents+0x73e/0x1580
ext4_ext_map_blocks+0xe20/0x2dc0
ext4_map_blocks+0x724/0x1700
ext4_do_writepages+0x12d6/0x2a70
[...]
==================================================================
The flow of issue triggering is as follows:
ext4_split_extent_at
path = *ppath
ext4_ext_insert_extent(ppath)
ext4_ext_create_new_leaf(ppath)
ext4_find_extent(orig_path)
path = *orig_path
read_extent_tree_block
// return -ENOMEM or -EIO
ext4_free_ext_path(path)
kfree(path)
*orig_path = NULL
a. If err is -ENOMEM:
ext4_ext_dirty(path + path->p_depth)
// path use-after-free !!!
b. If err is -EIO and we have EXT_DEBUG defined:
ext4_ext_show_leaf(path)
eh = path[depth].p_hdr
// path also use-after-free !!!
So when trying to zeroout or fix the extent length, call ext4_find_extent()
to update the path.
In addition we use *ppath directly as an ext4_ext_show_leaf() input to
avoid possible use-after-free when EXT_DEBUG is defined, and to avoid
unnecessary path updates. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: aovid use-after-free in ext4_ext_insert_extent()
As Ojaswin mentioned in Link, in ext4_ext_insert_extent(), if the path is
reallocated in ext4_ext_create_new_leaf(), we'll use the stale path and
cause UAF. Below is a sample trace with dummy values:
ext4_ext_insert_extent
path = *ppath = 2000
ext4_ext_create_new_leaf(ppath)
ext4_find_extent(ppath)
path = *ppath = 2000
if (depth > path[0].p_maxdepth)
kfree(path = 2000);
*ppath = path = NULL;
path = kcalloc() = 3000
*ppath = 3000;
return path;
/* here path is still 2000, UAF! */
eh = path[depth].p_hdr
==================================================================
BUG: KASAN: slab-use-after-free in ext4_ext_insert_extent+0x26d4/0x3330
Read of size 8 at addr ffff8881027bf7d0 by task kworker/u36:1/179
CPU: 3 UID: 0 PID: 179 Comm: kworker/u6:1 Not tainted 6.11.0-rc2-dirty #866
Call Trace:
<TASK>
ext4_ext_insert_extent+0x26d4/0x3330
ext4_ext_map_blocks+0xe22/0x2d40
ext4_map_blocks+0x71e/0x1700
ext4_do_writepages+0x1290/0x2800
[...]
Allocated by task 179:
ext4_find_extent+0x81c/0x1f70
ext4_ext_map_blocks+0x146/0x2d40
ext4_map_blocks+0x71e/0x1700
ext4_do_writepages+0x1290/0x2800
ext4_writepages+0x26d/0x4e0
do_writepages+0x175/0x700
[...]
Freed by task 179:
kfree+0xcb/0x240
ext4_find_extent+0x7c0/0x1f70
ext4_ext_insert_extent+0xa26/0x3330
ext4_ext_map_blocks+0xe22/0x2d40
ext4_map_blocks+0x71e/0x1700
ext4_do_writepages+0x1290/0x2800
ext4_writepages+0x26d/0x4e0
do_writepages+0x175/0x700
[...]
==================================================================
So use *ppath to update the path to avoid the above problem. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: fix double brelse() the buffer of the extents path
In ext4_ext_try_to_merge_up(), set path[1].p_bh to NULL after it has been
released, otherwise it may be released twice. An example of what triggers
this is as follows:
split2 map split1
|--------|-------|--------|
ext4_ext_map_blocks
ext4_ext_handle_unwritten_extents
ext4_split_convert_extents
// path->p_depth == 0
ext4_split_extent
// 1. do split1
ext4_split_extent_at
|ext4_ext_insert_extent
| ext4_ext_create_new_leaf
| ext4_ext_grow_indepth
| le16_add_cpu(&neh->eh_depth, 1)
| ext4_find_extent
| // return -ENOMEM
|// get error and try zeroout
|path = ext4_find_extent
| path->p_depth = 1
|ext4_ext_try_to_merge
| ext4_ext_try_to_merge_up
| path->p_depth = 0
| brelse(path[1].p_bh) ---> not set to NULL here
|// zeroout success
// 2. update path
ext4_find_extent
// 3. do split2
ext4_split_extent_at
ext4_ext_insert_extent
ext4_ext_create_new_leaf
ext4_ext_grow_indepth
le16_add_cpu(&neh->eh_depth, 1)
ext4_find_extent
path[0].p_bh = NULL;
path->p_depth = 1
read_extent_tree_block ---> return err
// path[1].p_bh is still the old value
ext4_free_ext_path
ext4_ext_drop_refs
// path->p_depth == 1
brelse(path[1].p_bh) ---> brelse a buffer twice
Finally got the following WARRNING when removing the buffer from lru:
============================================
VFS: brelse: Trying to free free buffer
WARNING: CPU: 2 PID: 72 at fs/buffer.c:1241 __brelse+0x58/0x90
CPU: 2 PID: 72 Comm: kworker/u19:1 Not tainted 6.9.0-dirty #716
RIP: 0010:__brelse+0x58/0x90
Call Trace:
<TASK>
__find_get_block+0x6e7/0x810
bdev_getblk+0x2b/0x480
__ext4_get_inode_loc+0x48a/0x1240
ext4_get_inode_loc+0xb2/0x150
ext4_reserve_inode_write+0xb7/0x230
__ext4_mark_inode_dirty+0x144/0x6a0
ext4_ext_insert_extent+0x9c8/0x3230
ext4_ext_map_blocks+0xf45/0x2dc0
ext4_map_blocks+0x724/0x1700
ext4_do_writepages+0x12d6/0x2a70
[...]
============================================ |
| In the Linux kernel, the following vulnerability has been resolved:
mm: call the security_mmap_file() LSM hook in remap_file_pages()
The remap_file_pages syscall handler calls do_mmap() directly, which
doesn't contain the LSM security check. And if the process has called
personality(READ_IMPLIES_EXEC) before and remap_file_pages() is called for
RW pages, this will actually result in remapping the pages to RWX,
bypassing a W^X policy enforced by SELinux.
So we should check prot by security_mmap_file LSM hook in the
remap_file_pages syscall handler before do_mmap() is called. Otherwise, it
potentially permits an attacker to bypass a W^X policy enforced by
SELinux.
The bypass is similar to CVE-2016-10044, which bypass the same thing via
AIO and can be found in [1].
The PoC:
$ cat > test.c
int main(void) {
size_t pagesz = sysconf(_SC_PAGE_SIZE);
int mfd = syscall(SYS_memfd_create, "test", 0);
const char *buf = mmap(NULL, 4 * pagesz, PROT_READ | PROT_WRITE,
MAP_SHARED, mfd, 0);
unsigned int old = syscall(SYS_personality, 0xffffffff);
syscall(SYS_personality, READ_IMPLIES_EXEC | old);
syscall(SYS_remap_file_pages, buf, pagesz, 0, 2, 0);
syscall(SYS_personality, old);
// show the RWX page exists even if W^X policy is enforced
int fd = open("/proc/self/maps", O_RDONLY);
unsigned char buf2[1024];
while (1) {
int ret = read(fd, buf2, 1024);
if (ret <= 0) break;
write(1, buf2, ret);
}
close(fd);
}
$ gcc test.c -o test
$ ./test | grep rwx
7f1836c34000-7f1836c35000 rwxs 00002000 00:01 2050 /memfd:test (deleted)
[PM: subject line tweaks] |
| In the Linux kernel, the following vulnerability has been resolved:
firmware_loader: Block path traversal
Most firmware names are hardcoded strings, or are constructed from fairly
constrained format strings where the dynamic parts are just some hex
numbers or such.
However, there are a couple codepaths in the kernel where firmware file
names contain string components that are passed through from a device or
semi-privileged userspace; the ones I could find (not counting interfaces
that require root privileges) are:
- lpfc_sli4_request_firmware_update() seems to construct the firmware
filename from "ModelName", a string that was previously parsed out of
some descriptor ("Vital Product Data") in lpfc_fill_vpd()
- nfp_net_fw_find() seems to construct a firmware filename from a model
name coming from nfp_hwinfo_lookup(pf->hwinfo, "nffw.partno"), which I
think parses some descriptor that was read from the device.
(But this case likely isn't exploitable because the format string looks
like "netronome/nic_%s", and there shouldn't be any *folders* starting
with "netronome/nic_". The previous case was different because there,
the "%s" is *at the start* of the format string.)
- module_flash_fw_schedule() is reachable from the
ETHTOOL_MSG_MODULE_FW_FLASH_ACT netlink command, which is marked as
GENL_UNS_ADMIN_PERM (meaning CAP_NET_ADMIN inside a user namespace is
enough to pass the privilege check), and takes a userspace-provided
firmware name.
(But I think to reach this case, you need to have CAP_NET_ADMIN over a
network namespace that a special kind of ethernet device is mapped into,
so I think this is not a viable attack path in practice.)
Fix it by rejecting any firmware names containing ".." path components.
For what it's worth, I went looking and haven't found any USB device
drivers that use the firmware loader dangerously. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: hisilicon/qm - inject error before stopping queue
The master ooo cannot be completely closed when the
accelerator core reports memory error. Therefore, the driver
needs to inject the qm error to close the master ooo. Currently,
the qm error is injected after stopping queue, memory may be
released immediately after stopping queue, causing the device to
access the released memory. Therefore, error is injected to close master
ooo before stopping queue to ensure that the device does not access
the released memory. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: core: zero-initialize the report buffer
Since the report buffer is used by all kinds of drivers in various ways, let's
zero-initialize it during allocation to make sure that it can't be ever used
to leak kernel memory via specially-crafted report. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/vmscape: Add conditional IBPB mitigation
VMSCAPE is a vulnerability that exploits insufficient branch predictor
isolation between a guest and a userspace hypervisor (like QEMU). Existing
mitigations already protect kernel/KVM from a malicious guest. Userspace
can additionally be protected by flushing the branch predictors after a
VMexit.
Since it is the userspace that consumes the poisoned branch predictors,
conditionally issue an IBPB after a VMexit and before returning to
userspace. Workloads that frequently switch between hypervisor and
userspace will incur the most overhead from the new IBPB.
This new IBPB is not integrated with the existing IBPB sites. For
instance, a task can use the existing speculation control prctl() to
get an IBPB at context switch time. With this implementation, the
IBPB is doubled up: one at context switch and another before running
userspace.
The intent is to integrate and optimize these cases post-embargo.
[ dhansen: elaborate on suboptimal IBPB solution ] |
