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CVSS v3.1 |
In the Linux kernel, the following vulnerability has been resolved:
mm, slub: avoid zeroing kmalloc redzone
Since commit 946fa0dbf2d8 ("mm/slub: extend redzone check to extra
allocated kmalloc space than requested"), setting orig_size treats
the wasted space (object_size - orig_size) as a redzone. However with
init_on_free=1 we clear the full object->size, including the redzone.
Additionally we clear the object metadata, including the stored orig_size,
making it zero, which makes check_object() treat the whole object as a
redzone.
These issues lead to the following BUG report with "slub_debug=FUZ
init_on_free=1":
[ 0.000000] =============================================================================
[ 0.000000] BUG kmalloc-8 (Not tainted): kmalloc Redzone overwritten
[ 0.000000] -----------------------------------------------------------------------------
[ 0.000000]
[ 0.000000] 0xffff000010032858-0xffff00001003285f @offset=2136. First byte 0x0 instead of 0xcc
[ 0.000000] FIX kmalloc-8: Restoring kmalloc Redzone 0xffff000010032858-0xffff00001003285f=0xcc
[ 0.000000] Slab 0xfffffdffc0400c80 objects=36 used=23 fp=0xffff000010032a18 flags=0x3fffe0000000200(workingset|node=0|zone=0|lastcpupid=0x1ffff)
[ 0.000000] Object 0xffff000010032858 @offset=2136 fp=0xffff0000100328c8
[ 0.000000]
[ 0.000000] Redzone ffff000010032850: cc cc cc cc cc cc cc cc ........
[ 0.000000] Object ffff000010032858: cc cc cc cc cc cc cc cc ........
[ 0.000000] Redzone ffff000010032860: cc cc cc cc cc cc cc cc ........
[ 0.000000] Padding ffff0000100328b4: 00 00 00 00 00 00 00 00 00 00 00 00 ............
[ 0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.11.0-rc3-next-20240814-00004-g61844c55c3f4 #144
[ 0.000000] Hardware name: NXP i.MX95 19X19 board (DT)
[ 0.000000] Call trace:
[ 0.000000] dump_backtrace+0x90/0xe8
[ 0.000000] show_stack+0x18/0x24
[ 0.000000] dump_stack_lvl+0x74/0x8c
[ 0.000000] dump_stack+0x18/0x24
[ 0.000000] print_trailer+0x150/0x218
[ 0.000000] check_object+0xe4/0x454
[ 0.000000] free_to_partial_list+0x2f8/0x5ec
To address the issue, use orig_size to clear the used area. And restore
the value of orig_size after clear the remaining area.
When CONFIG_SLUB_DEBUG not defined, (get_orig_size()' directly returns
s->object_size. So when using memset to init the area, the size can simply
be orig_size, as orig_size returns object_size when CONFIG_SLUB_DEBUG not
enabled. And orig_size can never be bigger than object_size. |
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:
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:
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:
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:
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:
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:
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. |
In the Linux kernel, the following vulnerability has been resolved:
x86/sgx: Fix deadlock in SGX NUMA node search
When the current node doesn't have an EPC section configured by firmware
and all other EPC sections are used up, CPU can get stuck inside the
while loop that looks for an available EPC page from remote nodes
indefinitely, leading to a soft lockup. Note how nid_of_current will
never be equal to nid in that while loop because nid_of_current is not
set in sgx_numa_mask.
Also worth mentioning is that it's perfectly fine for the firmware not
to setup an EPC section on a node. While setting up an EPC section on
each node can enhance performance, it is not a requirement for
functionality.
Rework the loop to start and end on *a* node that has SGX memory. This
avoids the deadlock looking for the current SGX-lacking node to show up
in the loop when it never will. |
In the Linux kernel, the following vulnerability has been resolved:
tpm: Clean up TPM space after command failure
tpm_dev_transmit prepares the TPM space before attempting command
transmission. However if the command fails no rollback of this
preparation is done. This can result in transient handles being leaked
if the device is subsequently closed with no further commands performed.
Fix this by flushing the space in the event of command transmission
failure. |
In the Linux kernel, the following vulnerability has been resolved:
wifi: rtw89: check return value of ieee80211_probereq_get() for RNR
The return value of ieee80211_probereq_get() might be NULL, so check it
before using to avoid NULL pointer access.
Addresses-Coverity-ID: 1529805 ("Dereference null return value") |
In the Linux kernel, the following vulnerability has been resolved:
vhost_vdpa: assign irq bypass producer token correctly
We used to call irq_bypass_unregister_producer() in
vhost_vdpa_setup_vq_irq() which is problematic as we don't know if the
token pointer is still valid or not.
Actually, we use the eventfd_ctx as the token so the life cycle of the
token should be bound to the VHOST_SET_VRING_CALL instead of
vhost_vdpa_setup_vq_irq() which could be called by set_status().
Fixing this by setting up irq bypass producer's token when handling
VHOST_SET_VRING_CALL and un-registering the producer before calling
vhost_vring_ioctl() to prevent a possible use after free as eventfd
could have been released in vhost_vring_ioctl(). And such registering
and unregistering will only be done if DRIVER_OK is set. |
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:
padata: use integer wrap around to prevent deadlock on seq_nr overflow
When submitting more than 2^32 padata objects to padata_do_serial, the
current sorting implementation incorrectly sorts padata objects with
overflowed seq_nr, causing them to be placed before existing objects in
the reorder list. This leads to a deadlock in the serialization process
as padata_find_next cannot match padata->seq_nr and pd->processed
because the padata instance with overflowed seq_nr will be selected
next.
To fix this, we use an unsigned integer wrap around to correctly sort
padata objects in scenarios with integer overflow. |
In the Linux kernel, the following vulnerability has been resolved:
nfsd: call cache_put if xdr_reserve_space returns NULL
If not enough buffer space available, but idmap_lookup has triggered
lookup_fn which calls cache_get and returns successfully. Then we
missed to call cache_put here which pairs with cache_get.
Reviwed-by: Jeff Layton <jlayton@kernel.org> |
In the Linux kernel, the following vulnerability has been resolved:
iommufd: Protect against overflow of ALIGN() during iova allocation
Userspace can supply an iova and uptr such that the target iova alignment
becomes really big and ALIGN() overflows which corrupts the selected area
range during allocation. CONFIG_IOMMUFD_TEST can detect this:
WARNING: CPU: 1 PID: 5092 at drivers/iommu/iommufd/io_pagetable.c:268 iopt_alloc_area_pages drivers/iommu/iommufd/io_pagetable.c:268 [inline]
WARNING: CPU: 1 PID: 5092 at drivers/iommu/iommufd/io_pagetable.c:268 iopt_map_pages+0xf95/0x1050 drivers/iommu/iommufd/io_pagetable.c:352
Modules linked in:
CPU: 1 PID: 5092 Comm: syz-executor294 Not tainted 6.10.0-rc5-syzkaller-00294-g3ffea9a7a6f7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:iopt_alloc_area_pages drivers/iommu/iommufd/io_pagetable.c:268 [inline]
RIP: 0010:iopt_map_pages+0xf95/0x1050 drivers/iommu/iommufd/io_pagetable.c:352
Code: fc e9 a4 f3 ff ff e8 1a 8b 4c fc 41 be e4 ff ff ff e9 8a f3 ff ff e8 0a 8b 4c fc 90 0f 0b 90 e9 37 f5 ff ff e8 fc 8a 4c fc 90 <0f> 0b 90 e9 68 f3 ff ff 48 c7 c1 ec 82 ad 8f 80 e1 07 80 c1 03 38
RSP: 0018:ffffc90003ebf9e0 EFLAGS: 00010293
RAX: ffffffff85499fa4 RBX: 00000000ffffffef RCX: ffff888079b49e00
RDX: 0000000000000000 RSI: 00000000ffffffef RDI: 0000000000000000
RBP: ffffc90003ebfc50 R08: ffffffff85499b30 R09: ffffffff85499942
R10: 0000000000000002 R11: ffff888079b49e00 R12: ffff8880228e0010
R13: 0000000000000000 R14: 1ffff920007d7f68 R15: ffffc90003ebfd00
FS: 000055557d760380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000005fdeb8 CR3: 000000007404a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
iommufd_ioas_copy+0x610/0x7b0 drivers/iommu/iommufd/ioas.c:274
iommufd_fops_ioctl+0x4d9/0x5a0 drivers/iommu/iommufd/main.c:421
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xfc/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
Cap the automatic alignment to the huge page size, which is probably a
better idea overall. Huge automatic alignments can fragment and chew up
the available IOVA space without any reason. |
In the Linux kernel, the following vulnerability has been resolved:
wifi: rtw88: always wait for both firmware loading attempts
In 'rtw_wait_firmware_completion()', always wait for both (regular and
wowlan) firmware loading attempts. Otherwise if 'rtw_usb_intf_init()'
has failed in 'rtw_usb_probe()', 'rtw_usb_disconnect()' may issue
'ieee80211_free_hw()' when one of 'rtw_load_firmware_cb()' (usually
the wowlan one) is still in progress, causing UAF detected by KASAN. |
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7915: fix oops on non-dbdc mt7986
mt7915_band_config() sets band_idx = 1 on the main phy for mt7986
with MT7975_ONE_ADIE or MT7976_ONE_ADIE.
Commit 0335c034e726 ("wifi: mt76: fix race condition related to
checking tx queue fill status") introduced a dereference of the
phys array indirectly indexed by band_idx via wcid->phy_idx in
mt76_wcid_cleanup(). This caused the following Oops on affected
mt7986 devices:
Unable to handle kernel read from unreadable memory at virtual address 0000000000000024
Mem abort info:
ESR = 0x0000000096000005
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x05: level 1 translation fault
Data abort info:
ISV = 0, ISS = 0x00000005
CM = 0, WnR = 0
user pgtable: 4k pages, 39-bit VAs, pgdp=0000000042545000
[0000000000000024] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
Internal error: Oops: 0000000096000005 [#1] SMP
Modules linked in: ... mt7915e mt76_connac_lib mt76 mac80211 cfg80211 ...
CPU: 2 PID: 1631 Comm: hostapd Not tainted 5.15.150 #0
Hardware name: ZyXEL EX5700 (Telenor) (DT)
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : mt76_wcid_cleanup+0x84/0x22c [mt76]
lr : mt76_wcid_cleanup+0x64/0x22c [mt76]
sp : ffffffc00a803700
x29: ffffffc00a803700 x28: ffffff80008f7300 x27: ffffff80003f3c00
x26: ffffff80000a7880 x25: ffffffc008c26e00 x24: 0000000000000001
x23: ffffffc000a68114 x22: 0000000000000000 x21: ffffff8004172cc8
x20: ffffffc00a803748 x19: ffffff8004152020 x18: 0000000000000000
x17: 00000000000017c0 x16: ffffffc008ef5000 x15: 0000000000000be0
x14: ffffff8004172e28 x13: ffffff8004172e28 x12: 0000000000000000
x11: 0000000000000000 x10: ffffff8004172e30 x9 : ffffff8004172e28
x8 : 0000000000000000 x7 : ffffff8004156020 x6 : 0000000000000000
x5 : 0000000000000031 x4 : 0000000000000000 x3 : 0000000000000001
x2 : 0000000000000000 x1 : ffffff80008f7300 x0 : 0000000000000024
Call trace:
mt76_wcid_cleanup+0x84/0x22c [mt76]
__mt76_sta_remove+0x70/0xbc [mt76]
mt76_sta_state+0x8c/0x1a4 [mt76]
mt7915_eeprom_get_power_delta+0x11e4/0x23a0 [mt7915e]
drv_sta_state+0x144/0x274 [mac80211]
sta_info_move_state+0x1cc/0x2a4 [mac80211]
sta_set_sinfo+0xaf8/0xc24 [mac80211]
sta_info_destroy_addr_bss+0x4c/0x6c [mac80211]
ieee80211_color_change_finish+0x1c08/0x1e70 [mac80211]
cfg80211_check_station_change+0x1360/0x4710 [cfg80211]
genl_family_rcv_msg_doit+0xb4/0x110
genl_rcv_msg+0xd0/0x1bc
netlink_rcv_skb+0x58/0x120
genl_rcv+0x34/0x50
netlink_unicast+0x1f0/0x2ec
netlink_sendmsg+0x198/0x3d0
____sys_sendmsg+0x1b0/0x210
___sys_sendmsg+0x80/0xf0
__sys_sendmsg+0x44/0xa0
__arm64_sys_sendmsg+0x20/0x30
invoke_syscall.constprop.0+0x4c/0xe0
do_el0_svc+0x40/0xd0
el0_svc+0x14/0x4c
el0t_64_sync_handler+0x100/0x110
el0t_64_sync+0x15c/0x160
Code: d2800002 910092c0 52800023 f9800011 (885f7c01)
---[ end trace 7e42dd9a39ed2281 ]---
Fix by using mt76_dev_phy() which will map band_idx to the correct phy
for all hardware combinations. |