| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| 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:
drm: omapdrm: Add missing check for alloc_ordered_workqueue
As it may return NULL pointer and cause NULL pointer dereference. Add check
for the return value of alloc_ordered_workqueue. |
| 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:
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:
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:
i3c: master: svc: Fix use after free vulnerability in svc_i3c_master Driver Due to Race Condition
In the svc_i3c_master_probe function, &master->hj_work is bound with
svc_i3c_master_hj_work, &master->ibi_work is bound with
svc_i3c_master_ibi_work. And svc_i3c_master_ibi_work can start the
hj_work, svc_i3c_master_irq_handler can start the ibi_work.
If we remove the module which will call svc_i3c_master_remove to
make cleanup, it will free master->base through i3c_master_unregister
while the work mentioned above will be used. The sequence of operations
that may lead to a UAF bug is as follows:
CPU0 CPU1
| svc_i3c_master_hj_work
svc_i3c_master_remove |
i3c_master_unregister(&master->base)|
device_unregister(&master->dev) |
device_release |
//free master->base |
| i3c_master_do_daa(&master->base)
| //use master->base
Fix it by ensuring that the work is canceled before proceeding with the
cleanup in svc_i3c_master_remove. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/filemap: fix filemap_get_folios_contig THP panic
Patch series "memfd-pin huge page fixes".
Fix multiple bugs that occur when using memfd_pin_folios with hugetlb
pages and THP. The hugetlb bugs only bite when the page is not yet
faulted in when memfd_pin_folios is called. The THP bug bites when the
starting offset passed to memfd_pin_folios is not huge page aligned. See
the commit messages for details.
This patch (of 5):
memfd_pin_folios on memory backed by THP panics if the requested start
offset is not huge page aligned:
BUG: kernel NULL pointer dereference, address: 0000000000000036
RIP: 0010:filemap_get_folios_contig+0xdf/0x290
RSP: 0018:ffffc9002092fbe8 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 0000000000000002 RCX: 0000000000000002
The fault occurs here, because xas_load returns a folio with value 2:
filemap_get_folios_contig()
for (folio = xas_load(&xas); folio && xas.xa_index <= end;
folio = xas_next(&xas)) {
...
if (!folio_try_get(folio)) <-- BOOM
"2" is an xarray sibling entry. We get it because memfd_pin_folios does
not round the indices passed to filemap_get_folios_contig to huge page
boundaries for THP, so we load from the middle of a huge page range see a
sibling. (It does round for hugetlbfs, at the is_file_hugepages test).
To fix, if the folio is a sibling, then return the next index as the
starting point for the next call to filemap_get_folios_contig. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/gup: fix memfd_pin_folios alloc race panic
If memfd_pin_folios tries to create a hugetlb page, but someone else
already did, then folio gets the value -EEXIST here:
folio = memfd_alloc_folio(memfd, start_idx);
if (IS_ERR(folio)) {
ret = PTR_ERR(folio);
if (ret != -EEXIST)
goto err;
then on the next trip through the "while start_idx" loop we panic here:
if (folio) {
folio_put(folio);
To fix, set the folio to NULL on error. |
| 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. |
| 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:
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:
btrfs: fix a NULL pointer dereference when failed to start a new trasacntion
[BUG]
Syzbot reported a NULL pointer dereference with the following crash:
FAULT_INJECTION: forcing a failure.
start_transaction+0x830/0x1670 fs/btrfs/transaction.c:676
prepare_to_relocate+0x31f/0x4c0 fs/btrfs/relocation.c:3642
relocate_block_group+0x169/0xd20 fs/btrfs/relocation.c:3678
...
BTRFS info (device loop0): balance: ended with status: -12
Oops: general protection fault, probably for non-canonical address 0xdffffc00000000cc: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000660-0x0000000000000667]
RIP: 0010:btrfs_update_reloc_root+0x362/0xa80 fs/btrfs/relocation.c:926
Call Trace:
<TASK>
commit_fs_roots+0x2ee/0x720 fs/btrfs/transaction.c:1496
btrfs_commit_transaction+0xfaf/0x3740 fs/btrfs/transaction.c:2430
del_balance_item fs/btrfs/volumes.c:3678 [inline]
reset_balance_state+0x25e/0x3c0 fs/btrfs/volumes.c:3742
btrfs_balance+0xead/0x10c0 fs/btrfs/volumes.c:4574
btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3673
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
[CAUSE]
The allocation failure happens at the start_transaction() inside
prepare_to_relocate(), and during the error handling we call
unset_reloc_control(), which makes fs_info->balance_ctl to be NULL.
Then we continue the error path cleanup in btrfs_balance() by calling
reset_balance_state() which will call del_balance_item() to fully delete
the balance item in the root tree.
However during the small window between set_reloc_contrl() and
unset_reloc_control(), we can have a subvolume tree update and created a
reloc_root for that subvolume.
Then we go into the final btrfs_commit_transaction() of
del_balance_item(), and into btrfs_update_reloc_root() inside
commit_fs_roots().
That function checks if fs_info->reloc_ctl is in the merge_reloc_tree
stage, but since fs_info->reloc_ctl is NULL, it results a NULL pointer
dereference.
[FIX]
Just add extra check on fs_info->reloc_ctl inside
btrfs_update_reloc_root(), before checking
fs_info->reloc_ctl->merge_reloc_tree.
That DEAD_RELOC_TREE handling is to prevent further modification to the
reloc tree during merge stage, but since there is no reloc_ctl at all,
we do not need to bother that. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: wait for fixup workers before stopping cleaner kthread during umount
During unmount, at close_ctree(), we have the following steps in this order:
1) Park the cleaner kthread - this doesn't destroy the kthread, it basically
halts its execution (wake ups against it work but do nothing);
2) We stop the cleaner kthread - this results in freeing the respective
struct task_struct;
3) We call btrfs_stop_all_workers() which waits for any jobs running in all
the work queues and then free the work queues.
Syzbot reported a case where a fixup worker resulted in a crash when doing
a delayed iput on its inode while attempting to wake up the cleaner at
btrfs_add_delayed_iput(), because the task_struct of the cleaner kthread
was already freed. This can happen during unmount because we don't wait
for any fixup workers still running before we call kthread_stop() against
the cleaner kthread, which stops and free all its resources.
Fix this by waiting for any fixup workers at close_ctree() before we call
kthread_stop() against the cleaner and run pending delayed iputs.
The stack traces reported by syzbot were the following:
BUG: KASAN: slab-use-after-free in __lock_acquire+0x77/0x2050 kernel/locking/lockdep.c:5065
Read of size 8 at addr ffff8880272a8a18 by task kworker/u8:3/52
CPU: 1 UID: 0 PID: 52 Comm: kworker/u8:3 Not tainted 6.12.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: btrfs-fixup btrfs_work_helper
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x169/0x550 mm/kasan/report.c:488
kasan_report+0x143/0x180 mm/kasan/report.c:601
__lock_acquire+0x77/0x2050 kernel/locking/lockdep.c:5065
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline]
try_to_wake_up+0xb0/0x1480 kernel/sched/core.c:4154
btrfs_writepage_fixup_worker+0xc16/0xdf0 fs/btrfs/inode.c:2842
btrfs_work_helper+0x390/0xc50 fs/btrfs/async-thread.c:314
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
worker_thread+0x870/0xd30 kernel/workqueue.c:3391
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
Allocated by task 2:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:247 [inline]
slab_post_alloc_hook mm/slub.c:4086 [inline]
slab_alloc_node mm/slub.c:4135 [inline]
kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4187
alloc_task_struct_node kernel/fork.c:180 [inline]
dup_task_struct+0x57/0x8c0 kernel/fork.c:1107
copy_process+0x5d1/0x3d50 kernel/fork.c:2206
kernel_clone+0x223/0x880 kernel/fork.c:2787
kernel_thread+0x1bc/0x240 kernel/fork.c:2849
create_kthread kernel/kthread.c:412 [inline]
kthreadd+0x60d/0x810 kernel/kthread.c:765
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Freed by task 61:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_h
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
tracing/timerlat: Fix a race during cpuhp processing
There is another found exception that the "timerlat/1" thread was
scheduled on CPU0, and lead to timer corruption finally:
```
ODEBUG: init active (active state 0) object: ffff888237c2e108 object type: hrtimer hint: timerlat_irq+0x0/0x220
WARNING: CPU: 0 PID: 426 at lib/debugobjects.c:518 debug_print_object+0x7d/0xb0
Modules linked in:
CPU: 0 UID: 0 PID: 426 Comm: timerlat/1 Not tainted 6.11.0-rc7+ #45
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:debug_print_object+0x7d/0xb0
...
Call Trace:
<TASK>
? __warn+0x7c/0x110
? debug_print_object+0x7d/0xb0
? report_bug+0xf1/0x1d0
? prb_read_valid+0x17/0x20
? handle_bug+0x3f/0x70
? exc_invalid_op+0x13/0x60
? asm_exc_invalid_op+0x16/0x20
? debug_print_object+0x7d/0xb0
? debug_print_object+0x7d/0xb0
? __pfx_timerlat_irq+0x10/0x10
__debug_object_init+0x110/0x150
hrtimer_init+0x1d/0x60
timerlat_main+0xab/0x2d0
? __pfx_timerlat_main+0x10/0x10
kthread+0xb7/0xe0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x2d/0x40
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
```
After tracing the scheduling event, it was discovered that the migration
of the "timerlat/1" thread was performed during thread creation. Further
analysis confirmed that it is because the CPU online processing for
osnoise is implemented through workers, which is asynchronous with the
offline processing. When the worker was scheduled to create a thread, the
CPU may has already been removed from the cpu_online_mask during the offline
process, resulting in the inability to select the right CPU:
T1 | T2
[CPUHP_ONLINE] | cpu_device_down()
osnoise_hotplug_workfn() |
| cpus_write_lock()
| takedown_cpu(1)
| cpus_write_unlock()
[CPUHP_OFFLINE] |
cpus_read_lock() |
start_kthread(1) |
cpus_read_unlock() |
To fix this, skip online processing if the CPU is already offline. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/vm: move xa_alloc to prevent UAF
Evil user can guess the next id of the vm before the ioctl completes and
then call vm destroy ioctl to trigger UAF since create ioctl is still
referencing the same vm. Move the xa_alloc all the way to the end to
prevent this.
v2:
- Rebase
(cherry picked from commit dcfd3971327f3ee92765154baebbaece833d3ca9) |
| In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix a race between socket set up and I/O thread creation
In rxrpc_open_socket(), it sets up the socket and then sets up the I/O
thread that will handle it. This is a problem, however, as there's a gap
between the two phases in which a packet may come into rxrpc_encap_rcv()
from the UDP packet but we oops when trying to wake the not-yet created I/O
thread.
As a quick fix, just make rxrpc_encap_rcv() discard the packet if there's
no I/O thread yet.
A better, but more intrusive fix would perhaps be to rearrange things such
that the socket creation is done by the I/O thread. |
| In the Linux kernel, the following vulnerability has been resolved:
vhost/scsi: null-ptr-dereference in vhost_scsi_get_req()
Since commit 3f8ca2e115e5 ("vhost/scsi: Extract common handling code
from control queue handler") a null pointer dereference bug can be
triggered when guest sends an SCSI AN request.
In vhost_scsi_ctl_handle_vq(), `vc.target` is assigned with
`&v_req.tmf.lun[1]` within a switch-case block and is then passed to
vhost_scsi_get_req() which extracts `vc->req` and `tpg`. However, for
a `VIRTIO_SCSI_T_AN_*` request, tpg is not required, so `vc.target` is
set to NULL in this branch. Later, in vhost_scsi_get_req(),
`vc->target` is dereferenced without being checked, leading to a null
pointer dereference bug. This bug can be triggered from guest.
When this bug occurs, the vhost_worker process is killed while holding
`vq->mutex` and the corresponding tpg will remain occupied
indefinitely.
Below is the KASAN report:
Oops: general protection fault, probably for non-canonical address
0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 840 Comm: poc Not tainted 6.10.0+ #1
Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS
1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:vhost_scsi_get_req+0x165/0x3a0
Code: 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 2b 02 00 00
48 b8 00 00 00 00 00 fc ff df 4d 8b 65 30 4c 89 e2 48 c1 ea 03 <0f> b6
04 02 4c 89 e2 83 e2 07 38 d0 7f 08 84 c0 0f 85 be 01 00 00
RSP: 0018:ffff888017affb50 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88801b000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888017affcb8
RBP: ffff888017affb80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff888017affc88 R14: ffff888017affd1c R15: ffff888017993000
FS: 000055556e076500(0000) GS:ffff88806b100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200027c0 CR3: 0000000010ed0004 CR4: 0000000000370ef0
Call Trace:
<TASK>
? show_regs+0x86/0xa0
? die_addr+0x4b/0xd0
? exc_general_protection+0x163/0x260
? asm_exc_general_protection+0x27/0x30
? vhost_scsi_get_req+0x165/0x3a0
vhost_scsi_ctl_handle_vq+0x2a4/0xca0
? __pfx_vhost_scsi_ctl_handle_vq+0x10/0x10
? __switch_to+0x721/0xeb0
? __schedule+0xda5/0x5710
? __kasan_check_write+0x14/0x30
? _raw_spin_lock+0x82/0xf0
vhost_scsi_ctl_handle_kick+0x52/0x90
vhost_run_work_list+0x134/0x1b0
vhost_task_fn+0x121/0x350
...
</TASK>
---[ end trace 0000000000000000 ]---
Let's add a check in vhost_scsi_get_req.
[whitespace fixes] |
| In the Linux kernel, the following vulnerability has been resolved:
powercap: intel_rapl: Fix off by one in get_rpi()
The rp->priv->rpi array is either rpi_msr or rpi_tpmi which have
NR_RAPL_PRIMITIVES number of elements. Thus the > needs to be >=
to prevent an off by one access. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix helper writes to read-only maps
Lonial found an issue that despite user- and BPF-side frozen BPF map
(like in case of .rodata), it was still possible to write into it from
a BPF program side through specific helpers having ARG_PTR_TO_{LONG,INT}
as arguments.
In check_func_arg() when the argument is as mentioned, the meta->raw_mode
is never set. Later, check_helper_mem_access(), under the case of
PTR_TO_MAP_VALUE as register base type, it assumes BPF_READ for the
subsequent call to check_map_access_type() and given the BPF map is
read-only it succeeds.
The helpers really need to be annotated as ARG_PTR_TO_{LONG,INT} | MEM_UNINIT
when results are written into them as opposed to read out of them. The
latter indicates that it's okay to pass a pointer to uninitialized memory
as the memory is written to anyway.
However, ARG_PTR_TO_{LONG,INT} is a special case of ARG_PTR_TO_FIXED_SIZE_MEM
just with additional alignment requirement. So it is better to just get
rid of the ARG_PTR_TO_{LONG,INT} special cases altogether and reuse the
fixed size memory types. For this, add MEM_ALIGNED to additionally ensure
alignment given these helpers write directly into the args via *<ptr> = val.
The .arg*_size has been initialized reflecting the actual sizeof(*<ptr>).
MEM_ALIGNED can only be used in combination with MEM_FIXED_SIZE annotated
argument types, since in !MEM_FIXED_SIZE cases the verifier does not know
the buffer size a priori and therefore cannot blindly write *<ptr> = val. |
| In the Linux kernel, the following vulnerability has been resolved:
ACPI: sysfs: validate return type of _STR method
Only buffer objects are valid return values of _STR.
If something else is returned description_show() will access invalid
memory. |
