Security Vulnerabilities - CVEs Published In June 2024
In the Linux kernel, the following vulnerability has been resolved:
9p: add missing locking around taking dentry fid list
Fix a use-after-free on dentry's d_fsdata fid list when a thread
looks up a fid through dentry while another thread unlinks it:
UAF thread:
refcount_t: addition on 0; use-after-free.
p9_fid_get linux/./include/net/9p/client.h:262
v9fs_fid_find+0x236/0x280 linux/fs/9p/fid.c:129
v9fs_fid_lookup_with_uid linux/fs/9p/fid.c:181
v9fs_fid_lookup+0xbf/0xc20 linux/fs/9p/fid.c:314
v9fs_vfs_getattr_dotl+0xf9/0x360 linux/fs/9p/vfs_inode_dotl.c:400
vfs_statx+0xdd/0x4d0 linux/fs/stat.c:248
Freed by:
p9_fid_destroy (inlined)
p9_client_clunk+0xb0/0xe0 linux/net/9p/client.c:1456
p9_fid_put linux/./include/net/9p/client.h:278
v9fs_dentry_release+0xb5/0x140 linux/fs/9p/vfs_dentry.c:55
v9fs_remove+0x38f/0x620 linux/fs/9p/vfs_inode.c:518
vfs_unlink+0x29a/0x810 linux/fs/namei.c:4335
The problem is that d_fsdata was not accessed under d_lock, because
d_release() normally is only called once the dentry is otherwise no
longer accessible but since we also call it explicitly in v9fs_remove
that lock is required:
move the hlist out of the dentry under lock then unref its fids once
they are no longer accessible.
CVSS Score
7.8
EPSS Score
0.001
Published
2024-06-25
In the Linux kernel, the following vulnerability has been resolved:
media: v4l: async: Fix notifier list entry init
struct v4l2_async_notifier has several list_head members, but only
waiting_list and done_list are initialized. notifier_entry was kept
'zeroed' leading to an uninitialized list_head.
This results in a NULL-pointer dereference if csi2_async_register() fails,
e.g. node for remote endpoint is disabled, and returns -ENOTCONN.
The following calls to v4l2_async_nf_unregister() results in a NULL
pointer dereference.
Add the missing list head initializer.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-06-25
In the Linux kernel, the following vulnerability has been resolved:
genirq/irqdesc: Prevent use-after-free in irq_find_at_or_after()
irq_find_at_or_after() dereferences the interrupt descriptor which is
returned by mt_find() while neither holding sparse_irq_lock nor RCU read
lock, which means the descriptor can be freed between mt_find() and the
dereference:
CPU0 CPU1
desc = mt_find()
delayed_free_desc(desc)
irq_desc_get_irq(desc)
The use-after-free is reported by KASAN:
Call trace:
irq_get_next_irq+0x58/0x84
show_stat+0x638/0x824
seq_read_iter+0x158/0x4ec
proc_reg_read_iter+0x94/0x12c
vfs_read+0x1e0/0x2c8
Freed by task 4471:
slab_free_freelist_hook+0x174/0x1e0
__kmem_cache_free+0xa4/0x1dc
kfree+0x64/0x128
irq_kobj_release+0x28/0x3c
kobject_put+0xcc/0x1e0
delayed_free_desc+0x14/0x2c
rcu_do_batch+0x214/0x720
Guard the access with a RCU read lock section.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-06-25
In the Linux kernel, the following vulnerability has been resolved:
s390/ap: Fix crash in AP internal function modify_bitmap()
A system crash like this
Failing address: 200000cb7df6f000 TEID: 200000cb7df6f403
Fault in home space mode while using kernel ASCE.
AS:00000002d71bc007 R3:00000003fe5b8007 S:000000011a446000 P:000000015660c13d
Oops: 0038 ilc:3 [#1] PREEMPT SMP
Modules linked in: mlx5_ib ...
CPU: 8 PID: 7556 Comm: bash Not tainted 6.9.0-rc7 #8
Hardware name: IBM 3931 A01 704 (LPAR)
Krnl PSW : 0704e00180000000 0000014b75e7b606 (ap_parse_bitmap_str+0x10e/0x1f8)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
Krnl GPRS: 0000000000000001 ffffffffffffffc0 0000000000000001 00000048f96b75d3
000000cb00000100 ffffffffffffffff ffffffffffffffff 000000cb7df6fce0
000000cb7df6fce0 00000000ffffffff 000000000000002b 00000048ffffffff
000003ff9b2dbc80 200000cb7df6fcd8 0000014bffffffc0 000000cb7df6fbc8
Krnl Code: 0000014b75e7b5fc: a7840047 brc 8,0000014b75e7b68a
0000014b75e7b600: 18b2 lr %r11,%r2
#0000014b75e7b602: a7f4000a brc 15,0000014b75e7b616
>0000014b75e7b606: eb22d00000e6 laog %r2,%r2,0(%r13)
0000014b75e7b60c: a7680001 lhi %r6,1
0000014b75e7b610: 187b lr %r7,%r11
0000014b75e7b612: 84960021 brxh %r9,%r6,0000014b75e7b654
0000014b75e7b616: 18e9 lr %r14,%r9
Call Trace:
[<0000014b75e7b606>] ap_parse_bitmap_str+0x10e/0x1f8
([<0000014b75e7b5dc>] ap_parse_bitmap_str+0xe4/0x1f8)
[<0000014b75e7b758>] apmask_store+0x68/0x140
[<0000014b75679196>] kernfs_fop_write_iter+0x14e/0x1e8
[<0000014b75598524>] vfs_write+0x1b4/0x448
[<0000014b7559894c>] ksys_write+0x74/0x100
[<0000014b7618a440>] __do_syscall+0x268/0x328
[<0000014b761a3558>] system_call+0x70/0x98
INFO: lockdep is turned off.
Last Breaking-Event-Address:
[<0000014b75e7b636>] ap_parse_bitmap_str+0x13e/0x1f8
Kernel panic - not syncing: Fatal exception: panic_on_oops
occured when /sys/bus/ap/a[pq]mask was updated with a relative mask value
(like +0x10-0x12,+60,-90) with one of the numeric values exceeding INT_MAX.
The fix is simple: use unsigned long values for the internal variables. The
correct checks are already in place in the function but a simple int for
the internal variables was used with the possibility to overflow.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-06-25
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find()
Syzbot reports a warning as follows:
============================================
WARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290
Modules linked in:
CPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7
RIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419
Call Trace:
<TASK>
ext4_put_super+0x6d4/0xcd0 fs/ext4/super.c:1375
generic_shutdown_super+0x136/0x2d0 fs/super.c:641
kill_block_super+0x44/0x90 fs/super.c:1675
ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7327
[...]
============================================
This is because when finding an entry in ext4_xattr_block_cache_find(), if
ext4_sb_bread() returns -ENOMEM, the ce's e_refcnt, which has already grown
in the __entry_find(), won't be put away, and eventually trigger the above
issue in mb_cache_destroy() due to reference count leakage.
So call mb_cache_entry_put() on the -ENOMEM error branch as a quick fix.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-06-25
CVE-2024-37085
VMware ESXi contains an authentication bypass vulnerability. A malicious actor with sufficient Active Directory (AD) permissions can gain full access to an ESXi host that was previously configured to use AD for user management https://blogs.vmware.com/vsphere/2012/09/joining-vsphere-hosts-to-active-directory.html by re-creating the configured AD group ('ESXi Admins' by default) after it was deleted from AD.
Known exploited
CVSS Score
6.8
EPSS Score
0.537
Published
2024-06-25
VMware ESXi contains an out-of-bounds read vulnerability. A
malicious actor with local administrative privileges on a virtual
machine with an existing snapshot may trigger an out-of-bounds read
leading to a denial-of-service condition of the host.
CVSS Score
6.8
EPSS Score
0.0
Published
2024-06-25
The vCenter Server contains a denial-of-service vulnerability. A malicious actor with network access to vCenter Server may create a denial-of-service condition.
CVSS Score
5.3
EPSS Score
0.006
Published
2024-06-25
In the Linux kernel, the following vulnerability has been resolved:
x86/xen: Drop USERGS_SYSRET64 paravirt call
commit afd30525a659ac0ae0904f0cb4a2ca75522c3123 upstream.
USERGS_SYSRET64 is used to return from a syscall via SYSRET, but
a Xen PV guest will nevertheless use the IRET hypercall, as there
is no sysret PV hypercall defined.
So instead of testing all the prerequisites for doing a sysret and
then mangling the stack for Xen PV again for doing an iret just use
the iret exit from the beginning.
This can easily be done via an ALTERNATIVE like it is done for the
sysenter compat case already.
It should be noted that this drops the optimization in Xen for not
restoring a few registers when returning to user mode, but it seems
as if the saved instructions in the kernel more than compensate for
this drop (a kernel build in a Xen PV guest was slightly faster with
this patch applied).
While at it remove the stale sysret32 remnants.
[ pawan: Brad Spengler and Salvatore Bonaccorso <carnil@debian.org>
reported a problem with the 5.10 backport commit edc702b4a820
("x86/entry_64: Add VERW just before userspace transition").
When CONFIG_PARAVIRT_XXL=y, CLEAR_CPU_BUFFERS is not executed in
syscall_return_via_sysret path as USERGS_SYSRET64 is runtime
patched to:
.cpu_usergs_sysret64 = { 0x0f, 0x01, 0xf8,
0x48, 0x0f, 0x07 }, // swapgs; sysretq
which is missing CLEAR_CPU_BUFFERS. It turns out dropping
USERGS_SYSRET64 simplifies the code, allowing CLEAR_CPU_BUFFERS
to be explicitly added to syscall_return_via_sysret path. Below
is with CONFIG_PARAVIRT_XXL=y and this patch applied:
syscall_return_via_sysret:
...
<+342>: swapgs
<+345>: xchg %ax,%ax
<+347>: verw -0x1a2(%rip) <------
<+354>: sysretq
]
CVSS Score
8.8
EPSS Score
0.001
Published
2024-06-25
In the Linux kernel, the following vulnerability has been resolved:
media: lgdt3306a: Add a check against null-pointer-def
The driver should check whether the client provides the platform_data.
The following log reveals it:
[ 29.610324] BUG: KASAN: null-ptr-deref in kmemdup+0x30/0x40
[ 29.610730] Read of size 40 at addr 0000000000000000 by task bash/414
[ 29.612820] Call Trace:
[ 29.613030] <TASK>
[ 29.613201] dump_stack_lvl+0x56/0x6f
[ 29.613496] ? kmemdup+0x30/0x40
[ 29.613754] print_report.cold+0x494/0x6b7
[ 29.614082] ? kmemdup+0x30/0x40
[ 29.614340] kasan_report+0x8a/0x190
[ 29.614628] ? kmemdup+0x30/0x40
[ 29.614888] kasan_check_range+0x14d/0x1d0
[ 29.615213] memcpy+0x20/0x60
[ 29.615454] kmemdup+0x30/0x40
[ 29.615700] lgdt3306a_probe+0x52/0x310
[ 29.616339] i2c_device_probe+0x951/0xa90
CVSS Score
5.5
EPSS Score
0.001
Published
2024-06-25