Security Vulnerabilities - CVEs Published In February 2024
In the Linux kernel, the following vulnerability has been resolved:
media: pvrusb2: fix use after free on context disconnection
Upon module load, a kthread is created targeting the
pvr2_context_thread_func function, which may call pvr2_context_destroy
and thus call kfree() on the context object. However, that might happen
before the usb hub_event handler is able to notify the driver. This
patch adds a sanity check before the invalid read reported by syzbot,
within the context disconnection call stack.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-02-22
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix a race condition between btf_put() and map_free()
When running `./test_progs -j` in my local vm with latest kernel,
I once hit a kasan error like below:
[ 1887.184724] BUG: KASAN: slab-use-after-free in bpf_rb_root_free+0x1f8/0x2b0
[ 1887.185599] Read of size 4 at addr ffff888106806910 by task kworker/u12:2/2830
[ 1887.186498]
[ 1887.186712] CPU: 3 PID: 2830 Comm: kworker/u12:2 Tainted: G OEL 6.7.0-rc3-00699-g90679706d486-dirty #494
[ 1887.188034] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 1887.189618] Workqueue: events_unbound bpf_map_free_deferred
[ 1887.190341] Call Trace:
[ 1887.190666] <TASK>
[ 1887.190949] dump_stack_lvl+0xac/0xe0
[ 1887.191423] ? nf_tcp_handle_invalid+0x1b0/0x1b0
[ 1887.192019] ? panic+0x3c0/0x3c0
[ 1887.192449] print_report+0x14f/0x720
[ 1887.192930] ? preempt_count_sub+0x1c/0xd0
[ 1887.193459] ? __virt_addr_valid+0xac/0x120
[ 1887.194004] ? bpf_rb_root_free+0x1f8/0x2b0
[ 1887.194572] kasan_report+0xc3/0x100
[ 1887.195085] ? bpf_rb_root_free+0x1f8/0x2b0
[ 1887.195668] bpf_rb_root_free+0x1f8/0x2b0
[ 1887.196183] ? __bpf_obj_drop_impl+0xb0/0xb0
[ 1887.196736] ? preempt_count_sub+0x1c/0xd0
[ 1887.197270] ? preempt_count_sub+0x1c/0xd0
[ 1887.197802] ? _raw_spin_unlock+0x1f/0x40
[ 1887.198319] bpf_obj_free_fields+0x1d4/0x260
[ 1887.198883] array_map_free+0x1a3/0x260
[ 1887.199380] bpf_map_free_deferred+0x7b/0xe0
[ 1887.199943] process_scheduled_works+0x3a2/0x6c0
[ 1887.200549] worker_thread+0x633/0x890
[ 1887.201047] ? __kthread_parkme+0xd7/0xf0
[ 1887.201574] ? kthread+0x102/0x1d0
[ 1887.202020] kthread+0x1ab/0x1d0
[ 1887.202447] ? pr_cont_work+0x270/0x270
[ 1887.202954] ? kthread_blkcg+0x50/0x50
[ 1887.203444] ret_from_fork+0x34/0x50
[ 1887.203914] ? kthread_blkcg+0x50/0x50
[ 1887.204397] ret_from_fork_asm+0x11/0x20
[ 1887.204913] </TASK>
[ 1887.204913] </TASK>
[ 1887.205209]
[ 1887.205416] Allocated by task 2197:
[ 1887.205881] kasan_set_track+0x3f/0x60
[ 1887.206366] __kasan_kmalloc+0x6e/0x80
[ 1887.206856] __kmalloc+0xac/0x1a0
[ 1887.207293] btf_parse_fields+0xa15/0x1480
[ 1887.207836] btf_parse_struct_metas+0x566/0x670
[ 1887.208387] btf_new_fd+0x294/0x4d0
[ 1887.208851] __sys_bpf+0x4ba/0x600
[ 1887.209292] __x64_sys_bpf+0x41/0x50
[ 1887.209762] do_syscall_64+0x4c/0xf0
[ 1887.210222] entry_SYSCALL_64_after_hwframe+0x63/0x6b
[ 1887.210868]
[ 1887.211074] Freed by task 36:
[ 1887.211460] kasan_set_track+0x3f/0x60
[ 1887.211951] kasan_save_free_info+0x28/0x40
[ 1887.212485] ____kasan_slab_free+0x101/0x180
[ 1887.213027] __kmem_cache_free+0xe4/0x210
[ 1887.213514] btf_free+0x5b/0x130
[ 1887.213918] rcu_core+0x638/0xcc0
[ 1887.214347] __do_softirq+0x114/0x37e
The error happens at bpf_rb_root_free+0x1f8/0x2b0:
00000000000034c0 <bpf_rb_root_free>:
; {
34c0: f3 0f 1e fa endbr64
34c4: e8 00 00 00 00 callq 0x34c9 <bpf_rb_root_free+0x9>
34c9: 55 pushq %rbp
34ca: 48 89 e5 movq %rsp, %rbp
...
; if (rec && rec->refcount_off >= 0 &&
36aa: 4d 85 ed testq %r13, %r13
36ad: 74 a9 je 0x3658 <bpf_rb_root_free+0x198>
36af: 49 8d 7d 10 leaq 0x10(%r13), %rdi
36b3: e8 00 00 00 00 callq 0x36b8 <bpf_rb_root_free+0x1f8>
<==== kasan function
36b8: 45 8b 7d 10 movl 0x10(%r13), %r15d
<==== use-after-free load
36bc: 45 85 ff testl %r15d, %r15d
36bf: 78 8c js 0x364d <bpf_rb_root_free+0x18d>
So the problem
---truncated---
CVSS Score
7.8
EPSS Score
0.0
Published
2024-02-22
In the Linux kernel, the following vulnerability has been resolved:
bpf: Defer the free of inner map when necessary
When updating or deleting an inner map in map array or map htab, the map
may still be accessed by non-sleepable program or sleepable program.
However bpf_map_fd_put_ptr() decreases the ref-counter of the inner map
directly through bpf_map_put(), if the ref-counter is the last one
(which is true for most cases), the inner map will be freed by
ops->map_free() in a kworker. But for now, most .map_free() callbacks
don't use synchronize_rcu() or its variants to wait for the elapse of a
RCU grace period, so after the invocation of ops->map_free completes,
the bpf program which is accessing the inner map may incur
use-after-free problem.
Fix the free of inner map by invoking bpf_map_free_deferred() after both
one RCU grace period and one tasks trace RCU grace period if the inner
map has been removed from the outer map before. The deferment is
accomplished by using call_rcu() or call_rcu_tasks_trace() when
releasing the last ref-counter of bpf map. The newly-added rcu_head
field in bpf_map shares the same storage space with work field to
reduce the size of bpf_map.
CVSS Score
6.7
EPSS Score
0.0
Published
2024-02-22
In the Linux kernel, the following vulnerability has been resolved:
gfs2: Fix kernel NULL pointer dereference in gfs2_rgrp_dump
Syzkaller has reported a NULL pointer dereference when accessing
rgd->rd_rgl in gfs2_rgrp_dump(). This can happen when creating
rgd->rd_gl fails in read_rindex_entry(). Add a NULL pointer check in
gfs2_rgrp_dump() to prevent that.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-02-22
In the Linux kernel, the following vulnerability has been resolved:
mtd: Fix gluebi NULL pointer dereference caused by ftl notifier
If both ftl.ko and gluebi.ko are loaded, the notifier of ftl
triggers NULL pointer dereference when trying to access
‘gluebi->desc’ in gluebi_read().
ubi_gluebi_init
ubi_register_volume_notifier
ubi_enumerate_volumes
ubi_notify_all
gluebi_notify nb->notifier_call()
gluebi_create
mtd_device_register
mtd_device_parse_register
add_mtd_device
blktrans_notify_add not->add()
ftl_add_mtd tr->add_mtd()
scan_header
mtd_read
mtd_read_oob
mtd_read_oob_std
gluebi_read mtd->read()
gluebi->desc - NULL
Detailed reproduction information available at the Link [1],
In the normal case, obtain gluebi->desc in the gluebi_get_device(),
and access gluebi->desc in the gluebi_read(). However,
gluebi_get_device() is not executed in advance in the
ftl_add_mtd() process, which leads to NULL pointer dereference.
The solution for the gluebi module is to run jffs2 on the UBI
volume without considering working with ftl or mtdblock [2].
Therefore, this problem can be avoided by preventing gluebi from
creating the mtdblock device after creating mtd partition of the
type MTD_UBIVOLUME.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-02-22
In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel/uncore: Fix NULL pointer dereference issue in upi_fill_topology()
Get logical socket id instead of physical id in discover_upi_topology()
to avoid out-of-bound access on 'upi = &type->topology[nid][idx];' line
that leads to NULL pointer dereference in upi_fill_topology()
CVSS Score
5.5
EPSS Score
0.0
Published
2024-02-22
In the Linux kernel, the following vulnerability has been resolved:
powerpc/pseries/memhp: Fix access beyond end of drmem array
dlpar_memory_remove_by_index() may access beyond the bounds of the
drmem lmb array when the LMB lookup fails to match an entry with the
given DRC index. When the search fails, the cursor is left pointing to
&drmem_info->lmbs[drmem_info->n_lmbs], which is one element past the
last valid entry in the array. The debug message at the end of the
function then dereferences this pointer:
pr_debug("Failed to hot-remove memory at %llx\n",
lmb->base_addr);
This was found by inspection and confirmed with KASAN:
pseries-hotplug-mem: Attempting to hot-remove LMB, drc index 1234
==================================================================
BUG: KASAN: slab-out-of-bounds in dlpar_memory+0x298/0x1658
Read of size 8 at addr c000000364e97fd0 by task bash/949
dump_stack_lvl+0xa4/0xfc (unreliable)
print_report+0x214/0x63c
kasan_report+0x140/0x2e0
__asan_load8+0xa8/0xe0
dlpar_memory+0x298/0x1658
handle_dlpar_errorlog+0x130/0x1d0
dlpar_store+0x18c/0x3e0
kobj_attr_store+0x68/0xa0
sysfs_kf_write+0xc4/0x110
kernfs_fop_write_iter+0x26c/0x390
vfs_write+0x2d4/0x4e0
ksys_write+0xac/0x1a0
system_call_exception+0x268/0x530
system_call_vectored_common+0x15c/0x2ec
Allocated by task 1:
kasan_save_stack+0x48/0x80
kasan_set_track+0x34/0x50
kasan_save_alloc_info+0x34/0x50
__kasan_kmalloc+0xd0/0x120
__kmalloc+0x8c/0x320
kmalloc_array.constprop.0+0x48/0x5c
drmem_init+0x2a0/0x41c
do_one_initcall+0xe0/0x5c0
kernel_init_freeable+0x4ec/0x5a0
kernel_init+0x30/0x1e0
ret_from_kernel_user_thread+0x14/0x1c
The buggy address belongs to the object at c000000364e80000
which belongs to the cache kmalloc-128k of size 131072
The buggy address is located 0 bytes to the right of
allocated 98256-byte region [c000000364e80000, c000000364e97fd0)
==================================================================
pseries-hotplug-mem: Failed to hot-remove memory at 0
Log failed lookups with a separate message and dereference the
cursor only when it points to a valid entry.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-02-22
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix accesses to uninit stack slots
Privileged programs are supposed to be able to read uninitialized stack
memory (ever since 6715df8d5) but, before this patch, these accesses
were permitted inconsistently. In particular, accesses were permitted
above state->allocated_stack, but not below it. In other words, if the
stack was already "large enough", the access was permitted, but
otherwise the access was rejected instead of being allowed to "grow the
stack". This undesired rejection was happening in two places:
- in check_stack_slot_within_bounds()
- in check_stack_range_initialized()
This patch arranges for these accesses to be permitted. A bunch of tests
that were relying on the old rejection had to change; all of them were
changed to add also run unprivileged, in which case the old behavior
persists. One tests couldn't be updated - global_func16 - because it
can't run unprivileged for other reasons.
This patch also fixes the tracking of the stack size for variable-offset
reads. This second fix is bundled in the same commit as the first one
because they're inter-related. Before this patch, writes to the stack
using registers containing a variable offset (as opposed to registers
with fixed, known values) were not properly contributing to the
function's needed stack size. As a result, it was possible for a program
to verify, but then to attempt to read out-of-bounds data at runtime
because a too small stack had been allocated for it.
Each function tracks the size of the stack it needs in
bpf_subprog_info.stack_depth, which is maintained by
update_stack_depth(). For regular memory accesses, check_mem_access()
was calling update_state_depth() but it was passing in only the fixed
part of the offset register, ignoring the variable offset. This was
incorrect; the minimum possible value of that register should be used
instead.
This tracking is now fixed by centralizing the tracking of stack size in
grow_stack_state(), and by lifting the calls to grow_stack_state() to
check_stack_access_within_bounds() as suggested by Andrii. The code is
now simpler and more convincingly tracks the correct maximum stack size.
check_stack_range_initialized() can now rely on enough stack having been
allocated for the access; this helps with the fix for the first issue.
A few tests were changed to also check the stack depth computation. The
one that fails without this patch is verifier_var_off:stack_write_priv_vs_unpriv.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-02-22
In the Linux kernel, the following vulnerability has been resolved:
mlxsw: spectrum_acl_tcam: Fix stack corruption
When tc filters are first added to a net device, the corresponding local
port gets bound to an ACL group in the device. The group contains a list
of ACLs. In turn, each ACL points to a different TCAM region where the
filters are stored. During forwarding, the ACLs are sequentially
evaluated until a match is found.
One reason to place filters in different regions is when they are added
with decreasing priorities and in an alternating order so that two
consecutive filters can never fit in the same region because of their
key usage.
In Spectrum-2 and newer ASICs the firmware started to report that the
maximum number of ACLs in a group is more than 16, but the layout of the
register that configures ACL groups (PAGT) was not updated to account
for that. It is therefore possible to hit stack corruption [1] in the
rare case where more than 16 ACLs in a group are required.
Fix by limiting the maximum ACL group size to the minimum between what
the firmware reports and the maximum ACLs that fit in the PAGT register.
Add a test case to make sure the machine does not crash when this
condition is hit.
[1]
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: mlxsw_sp_acl_tcam_group_update+0x116/0x120
[...]
dump_stack_lvl+0x36/0x50
panic+0x305/0x330
__stack_chk_fail+0x15/0x20
mlxsw_sp_acl_tcam_group_update+0x116/0x120
mlxsw_sp_acl_tcam_group_region_attach+0x69/0x110
mlxsw_sp_acl_tcam_vchunk_get+0x492/0xa20
mlxsw_sp_acl_tcam_ventry_add+0x25/0xe0
mlxsw_sp_acl_rule_add+0x47/0x240
mlxsw_sp_flower_replace+0x1a9/0x1d0
tc_setup_cb_add+0xdc/0x1c0
fl_hw_replace_filter+0x146/0x1f0
fl_change+0xc17/0x1360
tc_new_tfilter+0x472/0xb90
rtnetlink_rcv_msg+0x313/0x3b0
netlink_rcv_skb+0x58/0x100
netlink_unicast+0x244/0x390
netlink_sendmsg+0x1e4/0x440
____sys_sendmsg+0x164/0x260
___sys_sendmsg+0x9a/0xe0
__sys_sendmsg+0x7a/0xc0
do_syscall_64+0x40/0xe0
entry_SYSCALL_64_after_hwframe+0x63/0x6b
CVSS Score
6.7
EPSS Score
0.0
Published
2024-02-22
In the Linux kernel, the following vulnerability has been resolved:
net: netdevsim: don't try to destroy PHC on VFs
PHC gets initialized in nsim_init_netdevsim(), which
is only called if (nsim_dev_port_is_pf()).
Create a counterpart of nsim_init_netdevsim() and
move the mock_phc_destroy() there.
This fixes a crash trying to destroy netdevsim with
VFs instantiated, as caught by running the devlink.sh test:
BUG: kernel NULL pointer dereference, address: 00000000000000b8
RIP: 0010:mock_phc_destroy+0xd/0x30
Call Trace:
<TASK>
nsim_destroy+0x4a/0x70 [netdevsim]
__nsim_dev_port_del+0x47/0x70 [netdevsim]
nsim_dev_reload_destroy+0x105/0x120 [netdevsim]
nsim_drv_remove+0x2f/0xb0 [netdevsim]
device_release_driver_internal+0x1a1/0x210
bus_remove_device+0xd5/0x120
device_del+0x159/0x490
device_unregister+0x12/0x30
del_device_store+0x11a/0x1a0 [netdevsim]
kernfs_fop_write_iter+0x130/0x1d0
vfs_write+0x30b/0x4b0
ksys_write+0x69/0xf0
do_syscall_64+0xcc/0x1e0
entry_SYSCALL_64_after_hwframe+0x6f/0x77
CVSS Score
5.5
EPSS Score
0.0
Published
2024-02-22