Security Vulnerabilities
- CVEs Published In October 2024
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix off by one issue in alloc_flex_gd()
Wesley reported an issue:
==================================================================
EXT4-fs (dm-5): resizing filesystem from 7168 to 786432 blocks
------------[ cut here ]------------
kernel BUG at fs/ext4/resize.c:324!
CPU: 9 UID: 0 PID: 3576 Comm: resize2fs Not tainted 6.11.0+ #27
RIP: 0010:ext4_resize_fs+0x1212/0x12d0
Call Trace:
__ext4_ioctl+0x4e0/0x1800
ext4_ioctl+0x12/0x20
__x64_sys_ioctl+0x99/0xd0
x64_sys_call+0x1206/0x20d0
do_syscall_64+0x72/0x110
entry_SYSCALL_64_after_hwframe+0x76/0x7e
==================================================================
While reviewing the patch, Honza found that when adjusting resize_bg in
alloc_flex_gd(), it was possible for flex_gd->resize_bg to be bigger than
flexbg_size.
The reproduction of the problem requires the following:
o_group = flexbg_size * 2 * n;
o_size = (o_group + 1) * group_size;
n_group: [o_group + flexbg_size, o_group + flexbg_size * 2)
o_size = (n_group + 1) * group_size;
Take n=0,flexbg_size=16 as an example:
last:15
|o---------------|--------------n-|
o_group:0 resize to n_group:30
The corresponding reproducer is:
img=test.img
rm -f $img
truncate -s 600M $img
mkfs.ext4 -F $img -b 1024 -G 16 8M
dev=`losetup -f --show $img`
mkdir -p /tmp/test
mount $dev /tmp/test
resize2fs $dev 248M
Delete the problematic plus 1 to fix the issue, and add a WARN_ON_ONCE()
to prevent the issue from happening again.
[ Note: another reproucer which this commit fixes is:
img=test.img
rm -f $img
truncate -s 25MiB $img
mkfs.ext4 -b 4096 -E nodiscard,lazy_itable_init=0,lazy_journal_init=0 $img
truncate -s 3GiB $img
dev=`losetup -f --show $img`
mkdir -p /tmp/test
mount $dev /tmp/test
resize2fs $dev 3G
umount $dev
losetup -d $dev
-- TYT ]
In the Linux kernel, the following vulnerability has been resolved:
ext4: update orig_path in ext4_find_extent()
In ext4_find_extent(), if the path is not big enough, we free it and set
*orig_path to NULL. But after reallocating and successfully initializing
the path, we don't update *orig_path, in which case the caller gets a
valid path but a NULL ppath, and this may cause a NULL pointer dereference
or a path memory leak. For example:
ext4_split_extent
path = *ppath = 2000
ext4_find_extent
if (depth > path[0].p_maxdepth)
kfree(path = 2000);
*orig_path = path = NULL;
path = kcalloc() = 3000
ext4_split_extent_at(*ppath = NULL)
path = *ppath;
ex = path[depth].p_ext;
// NULL pointer dereference!
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000010
CPU: 6 UID: 0 PID: 576 Comm: fsstress Not tainted 6.11.0-rc2-dirty #847
RIP: 0010:ext4_split_extent_at+0x6d/0x560
Call Trace:
<TASK>
ext4_split_extent.isra.0+0xcb/0x1b0
ext4_ext_convert_to_initialized+0x168/0x6c0
ext4_ext_handle_unwritten_extents+0x325/0x4d0
ext4_ext_map_blocks+0x520/0xdb0
ext4_map_blocks+0x2b0/0x690
ext4_iomap_begin+0x20e/0x2c0
[...]
==================================================================
Therefore, *orig_path is updated when the extent lookup succeeds, so that
the caller can safely use path or *ppath.
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:
nfsd: map the EBADMSG to nfserr_io to avoid warning
Ext4 will throw -EBADMSG through ext4_readdir when a checksum error
occurs, resulting in the following WARNING.
Fix it by mapping EBADMSG to nfserr_io.
nfsd_buffered_readdir
iterate_dir // -EBADMSG -74
ext4_readdir // .iterate_shared
ext4_dx_readdir
ext4_htree_fill_tree
htree_dirblock_to_tree
ext4_read_dirblock
__ext4_read_dirblock
ext4_dirblock_csum_verify
warn_no_space_for_csum
__warn_no_space_for_csum
return ERR_PTR(-EFSBADCRC) // -EBADMSG -74
nfserrno // WARNING
[ 161.115610] ------------[ cut here ]------------
[ 161.116465] nfsd: non-standard errno: -74
[ 161.117315] WARNING: CPU: 1 PID: 780 at fs/nfsd/nfsproc.c:878 nfserrno+0x9d/0xd0
[ 161.118596] Modules linked in:
[ 161.119243] CPU: 1 PID: 780 Comm: nfsd Not tainted 5.10.0-00014-g79679361fd5d #138
[ 161.120684] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qe
mu.org 04/01/2014
[ 161.123601] RIP: 0010:nfserrno+0x9d/0xd0
[ 161.124676] Code: 0f 87 da 30 dd 00 83 e3 01 b8 00 00 00 05 75 d7 44 89 ee 48 c7 c7 c0 57 24 98 89 44 24 04 c6
05 ce 2b 61 03 01 e8 99 20 d8 00 <0f> 0b 8b 44 24 04 eb b5 4c 89 e6 48 c7 c7 a0 6d a4 99 e8 cc 15 33
[ 161.127797] RSP: 0018:ffffc90000e2f9c0 EFLAGS: 00010286
[ 161.128794] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[ 161.130089] RDX: 1ffff1103ee16f6d RSI: 0000000000000008 RDI: fffff520001c5f2a
[ 161.131379] RBP: 0000000000000022 R08: 0000000000000001 R09: ffff8881f70c1827
[ 161.132664] R10: ffffed103ee18304 R11: 0000000000000001 R12: 0000000000000021
[ 161.133949] R13: 00000000ffffffb6 R14: ffff8881317c0000 R15: ffffc90000e2fbd8
[ 161.135244] FS: 0000000000000000(0000) GS:ffff8881f7080000(0000) knlGS:0000000000000000
[ 161.136695] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 161.137761] CR2: 00007fcaad70b348 CR3: 0000000144256006 CR4: 0000000000770ee0
[ 161.139041] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 161.140291] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 161.141519] PKRU: 55555554
[ 161.142076] Call Trace:
[ 161.142575] ? __warn+0x9b/0x140
[ 161.143229] ? nfserrno+0x9d/0xd0
[ 161.143872] ? report_bug+0x125/0x150
[ 161.144595] ? handle_bug+0x41/0x90
[ 161.145284] ? exc_invalid_op+0x14/0x70
[ 161.146009] ? asm_exc_invalid_op+0x12/0x20
[ 161.146816] ? nfserrno+0x9d/0xd0
[ 161.147487] nfsd_buffered_readdir+0x28b/0x2b0
[ 161.148333] ? nfsd4_encode_dirent_fattr+0x380/0x380
[ 161.149258] ? nfsd_buffered_filldir+0xf0/0xf0
[ 161.150093] ? wait_for_concurrent_writes+0x170/0x170
[ 161.151004] ? generic_file_llseek_size+0x48/0x160
[ 161.151895] nfsd_readdir+0x132/0x190
[ 161.152606] ? nfsd4_encode_dirent_fattr+0x380/0x380
[ 161.153516] ? nfsd_unlink+0x380/0x380
[ 161.154256] ? override_creds+0x45/0x60
[ 161.155006] nfsd4_encode_readdir+0x21a/0x3d0
[ 161.155850] ? nfsd4_encode_readlink+0x210/0x210
[ 161.156731] ? write_bytes_to_xdr_buf+0x97/0xe0
[ 161.157598] ? __write_bytes_to_xdr_buf+0xd0/0xd0
[ 161.158494] ? lock_downgrade+0x90/0x90
[ 161.159232] ? nfs4svc_decode_voidarg+0x10/0x10
[ 161.160092] nfsd4_encode_operation+0x15a/0x440
[ 161.160959] nfsd4_proc_compound+0x718/0xe90
[ 161.161818] nfsd_dispatch+0x18e/0x2c0
[ 161.162586] svc_process_common+0x786/0xc50
[ 161.163403] ? nfsd_svc+0x380/0x380
[ 161.164137] ? svc_printk+0x160/0x160
[ 161.164846] ? svc_xprt_do_enqueue.part.0+0x365/0x380
[ 161.165808] ? nfsd_svc+0x380/0x380
[ 161.166523] ? rcu_is_watching+0x23/0x40
[ 161.167309] svc_process+0x1a5/0x200
[ 161.168019] nfsd+0x1f5/0x380
[ 161.168663] ? nfsd_shutdown_threads+0x260/0x260
[ 161.169554] kthread+0x1c4/0x210
[ 161.170224] ? kthread_insert_work_sanity_check+0x80/0x80
[ 161.171246] ret_from_fork+0x1f/0x30
In the Linux kernel, the following vulnerability has been resolved:
drm/xe: fix UAF around queue destruction
We currently do stuff like queuing the final destruction step on a
random system wq, which will outlive the driver instance. With bad
timing we can teardown the driver with one or more work workqueue still
being alive leading to various UAF splats. Add a fini step to ensure
user queues are properly torn down. At this point GuC should already be
nuked so queue itself should no longer be referenced from hw pov.
v2 (Matt B)
- Looks much safer to use a waitqueue and then just wait for the
xa_array to become empty before triggering the drain.
(cherry picked from commit 861108666cc0e999cffeab6aff17b662e68774e3)
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix possible null-ptr-deref in ocfs2_set_buffer_uptodate
When doing cleanup, if flags without OCFS2_BH_READAHEAD, it may trigger
NULL pointer dereference in the following ocfs2_set_buffer_uptodate() if
bh is NULL.
In the Linux kernel, the following vulnerability has been resolved:
resource: fix region_intersects() vs add_memory_driver_managed()
On a system with CXL memory, the resource tree (/proc/iomem) related to
CXL memory may look like something as follows.
490000000-50fffffff : CXL Window 0
490000000-50fffffff : region0
490000000-50fffffff : dax0.0
490000000-50fffffff : System RAM (kmem)
Because drivers/dax/kmem.c calls add_memory_driver_managed() during
onlining CXL memory, which makes "System RAM (kmem)" a descendant of "CXL
Window X". This confuses region_intersects(), which expects all "System
RAM" resources to be at the top level of iomem_resource. This can lead to
bugs.
For example, when the following command line is executed to write some
memory in CXL memory range via /dev/mem,
$ dd if=data of=/dev/mem bs=$((1 << 10)) seek=$((0x490000000 >> 10)) count=1
dd: error writing '/dev/mem': Bad address
1+0 records in
0+0 records out
0 bytes copied, 0.0283507 s, 0.0 kB/s
the command fails as expected. However, the error code is wrong. It
should be "Operation not permitted" instead of "Bad address". More
seriously, the /dev/mem permission checking in devmem_is_allowed() passes
incorrectly. Although the accessing is prevented later because ioremap()
isn't allowed to map system RAM, it is a potential security issue. During
command executing, the following warning is reported in the kernel log for
calling ioremap() on system RAM.
ioremap on RAM at 0x0000000490000000 - 0x0000000490000fff
WARNING: CPU: 2 PID: 416 at arch/x86/mm/ioremap.c:216 __ioremap_caller.constprop.0+0x131/0x35d
Call Trace:
memremap+0xcb/0x184
xlate_dev_mem_ptr+0x25/0x2f
write_mem+0x94/0xfb
vfs_write+0x128/0x26d
ksys_write+0xac/0xfe
do_syscall_64+0x9a/0xfd
entry_SYSCALL_64_after_hwframe+0x4b/0x53
The details of command execution process are as follows. In the above
resource tree, "System RAM" is a descendant of "CXL Window 0" instead of a
top level resource. So, region_intersects() will report no System RAM
resources in the CXL memory region incorrectly, because it only checks the
top level resources. Consequently, devmem_is_allowed() will return 1
(allow access via /dev/mem) for CXL memory region incorrectly.
Fortunately, ioremap() doesn't allow to map System RAM and reject the
access.
So, region_intersects() needs to be fixed to work correctly with the
resource tree with "System RAM" not at top level as above. To fix it, if
we found a unmatched resource in the top level, we will continue to search
matched resources in its descendant resources. So, we will not miss any
matched resources in resource tree anymore.
In the new implementation, an example resource tree
|------------- "CXL Window 0" ------------|
|-- "System RAM" --|
will behave similar as the following fake resource tree for
region_intersects(, IORESOURCE_SYSTEM_RAM, ),
|-- "System RAM" --||-- "CXL Window 0a" --|
Where "CXL Window 0a" is part of the original "CXL Window 0" that
isn't covered by "System RAM".
In the Linux kernel, the following vulnerability has been resolved:
btrfs: send: fix buffer overflow detection when copying path to cache entry
Starting with commit c0247d289e73 ("btrfs: send: annotate struct
name_cache_entry with __counted_by()") we annotated the variable length
array "name" from the name_cache_entry structure with __counted_by() to
improve overflow detection. However that alone was not correct, because
the length of that array does not match the "name_len" field - it matches
that plus 1 to include the NUL string terminator, so that makes a
fortified kernel think there's an overflow and report a splat like this:
strcpy: detected buffer overflow: 20 byte write of buffer size 19
WARNING: CPU: 3 PID: 3310 at __fortify_report+0x45/0x50
CPU: 3 UID: 0 PID: 3310 Comm: btrfs Not tainted 6.11.0-prnet #1
Hardware name: CompuLab Ltd. sbc-ihsw/Intense-PC2 (IPC2), BIOS IPC2_3.330.7 X64 03/15/2018
RIP: 0010:__fortify_report+0x45/0x50
Code: 48 8b 34 (...)
RSP: 0018:ffff97ebc0d6f650 EFLAGS: 00010246
RAX: 7749924ef60fa600 RBX: ffff8bf5446a521a RCX: 0000000000000027
RDX: 00000000ffffdfff RSI: ffff97ebc0d6f548 RDI: ffff8bf84e7a1cc8
RBP: ffff8bf548574080 R08: ffffffffa8c40e10 R09: 0000000000005ffd
R10: 0000000000000004 R11: ffffffffa8c70e10 R12: ffff8bf551eef400
R13: 0000000000000000 R14: 0000000000000013 R15: 00000000000003a8
FS: 00007fae144de8c0(0000) GS:ffff8bf84e780000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fae14691690 CR3: 00000001027a2003 CR4: 00000000001706f0
Call Trace:
<TASK>
? __warn+0x12a/0x1d0
? __fortify_report+0x45/0x50
? report_bug+0x154/0x1c0
? handle_bug+0x42/0x70
? exc_invalid_op+0x1a/0x50
? asm_exc_invalid_op+0x1a/0x20
? __fortify_report+0x45/0x50
__fortify_panic+0x9/0x10
__get_cur_name_and_parent+0x3bc/0x3c0
get_cur_path+0x207/0x3b0
send_extent_data+0x709/0x10d0
? find_parent_nodes+0x22df/0x25d0
? mas_nomem+0x13/0x90
? mtree_insert_range+0xa5/0x110
? btrfs_lru_cache_store+0x5f/0x1e0
? iterate_extent_inodes+0x52d/0x5a0
process_extent+0xa96/0x11a0
? __pfx_lookup_backref_cache+0x10/0x10
? __pfx_store_backref_cache+0x10/0x10
? __pfx_iterate_backrefs+0x10/0x10
? __pfx_check_extent_item+0x10/0x10
changed_cb+0x6fa/0x930
? tree_advance+0x362/0x390
? memcmp_extent_buffer+0xd7/0x160
send_subvol+0xf0a/0x1520
btrfs_ioctl_send+0x106b/0x11d0
? __pfx___clone_root_cmp_sort+0x10/0x10
_btrfs_ioctl_send+0x1ac/0x240
btrfs_ioctl+0x75b/0x850
__se_sys_ioctl+0xca/0x150
do_syscall_64+0x85/0x160
? __count_memcg_events+0x69/0x100
? handle_mm_fault+0x1327/0x15c0
? __se_sys_rt_sigprocmask+0xf1/0x180
? syscall_exit_to_user_mode+0x75/0xa0
? do_syscall_64+0x91/0x160
? do_user_addr_fault+0x21d/0x630
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fae145eeb4f
Code: 00 48 89 (...)
RSP: 002b:00007ffdf1cb09b0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fae145eeb4f
RDX: 00007ffdf1cb0ad0 RSI: 0000000040489426 RDI: 0000000000000004
RBP: 00000000000078fe R08: 00007fae144006c0 R09: 00007ffdf1cb0927
R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffdf1cb1ce8
R13: 0000000000000003 R14: 000055c499fab2e0 R15: 0000000000000004
</TASK>
Fix this by not storing the NUL string terminator since we don't actually
need it for name cache entries, this way "name_len" corresponds to the
actual size of the "name" array. This requires marking the "name" array
field with __nonstring and using memcpy() instead of strcpy() as
recommended by the guidelines at:
https://github.com/KSPP/linux/issues/90
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: fix dentry leak in cachefiles_open_file()
A dentry leak may be caused when a lookup cookie and a cull are concurrent:
P1 | P2
-----------------------------------------------------------
cachefiles_lookup_cookie
cachefiles_look_up_object
lookup_one_positive_unlocked
// get dentry
cachefiles_cull
inode->i_flags |= S_KERNEL_FILE;
cachefiles_open_file
cachefiles_mark_inode_in_use
__cachefiles_mark_inode_in_use
can_use = false
if (!(inode->i_flags & S_KERNEL_FILE))
can_use = true
return false
return false
// Returns an error but doesn't put dentry
After that the following WARNING will be triggered when the backend folder
is umounted:
==================================================================
BUG: Dentry 000000008ad87947{i=7a,n=Dx_1_1.img} still in use (1) [unmount of ext4 sda]
WARNING: CPU: 4 PID: 359261 at fs/dcache.c:1767 umount_check+0x5d/0x70
CPU: 4 PID: 359261 Comm: umount Not tainted 6.6.0-dirty #25
RIP: 0010:umount_check+0x5d/0x70
Call Trace:
<TASK>
d_walk+0xda/0x2b0
do_one_tree+0x20/0x40
shrink_dcache_for_umount+0x2c/0x90
generic_shutdown_super+0x20/0x160
kill_block_super+0x1a/0x40
ext4_kill_sb+0x22/0x40
deactivate_locked_super+0x35/0x80
cleanup_mnt+0x104/0x160
==================================================================
Whether cachefiles_open_file() returns true or false, the reference count
obtained by lookup_positive_unlocked() in cachefiles_look_up_object()
should be released.
Therefore release that reference count in cachefiles_look_up_object() to
fix the above issue and simplify the code.
In the Linux kernel, the following vulnerability has been resolved:
Input: adp5589-keys - fix NULL pointer dereference
We register a devm action to call adp5589_clear_config() and then pass
the i2c client as argument so that we can call i2c_get_clientdata() in
order to get our device object. However, i2c_set_clientdata() is only
being set at the end of the probe function which means that we'll get a
NULL pointer dereference in case the probe function fails early.