An issue was discovered in libexpat before 2.6.4. There is a crash within the XML_ResumeParser function because XML_StopParser can stop/suspend an unstarted parser. |
In the Linux kernel, the following vulnerability has been resolved:
bpf: Prevent tail call between progs attached to different hooks
bpf progs can be attached to kernel functions, and the attached functions
can take di...Show moreIn the Linux kernel, the following vulnerability has been resolved:
bpf: Prevent tail call between progs attached to different hooks
bpf progs can be attached to kernel functions, and the attached functions
can take different parameters or return different return values. If
prog attached to one kernel function tail calls prog attached to another
kernel function, the ctx access or return value verification could be
bypassed.
For example, if prog1 is attached to func1 which takes only 1 parameter
and prog2 is attached to func2 which takes two parameters. Since verifier
assumes the bpf ctx passed to prog2 is constructed based on func2's
prototype, verifier allows prog2 to access the second parameter from
the bpf ctx passed to it. The problem is that verifier does not prevent
prog1 from passing its bpf ctx to prog2 via tail call. In this case,
the bpf ctx passed to prog2 is constructed from func1 instead of func2,
that is, the assumption for ctx access verification is bypassed.
Another example, if BPF LSM prog1 is attached to hook file_alloc_security,
and BPF LSM prog2 is attached to hook bpf_lsm_audit_rule_known. Verifier
knows the return value rules for these two hooks, e.g. it is legal for
bpf_lsm_audit_rule_known to return positive number 1, and it is illegal
for file_alloc_security to return positive number. So verifier allows
prog2 to return positive number 1, but does not allow prog1 to return
positive number. The problem is that verifier does not prevent prog1
from calling prog2 via tail call. In this case, prog2's return value 1
will be used as the return value for prog1's hook file_alloc_security.
That is, the return value rule is bypassed.
This patch adds restriction for tail call to prevent such bypasses.Show less |
In the Linux kernel, the following vulnerability has been resolved:
driver core: bus: Fix double free in driver API bus_register()
For bus_register(), any error which happens after kset_register() will
cause that @priv...Show moreIn the Linux kernel, the following vulnerability has been resolved:
driver core: bus: Fix double free in driver API bus_register()
For bus_register(), any error which happens after kset_register() will
cause that @priv are freed twice, fixed by setting @priv with NULL after
the first free.Show less |
In the Linux kernel, the following vulnerability has been resolved:
ALSA: asihpi: Fix potential OOB array access
ASIHPI driver stores some values in the static array upon a response
from the driver, and its index depen...Show moreIn the Linux kernel, the following vulnerability has been resolved:
ALSA: asihpi: Fix potential OOB array access
ASIHPI driver stores some values in the static array upon a response
from the driver, and its index depends on the firmware. We shouldn't
trust it blindly.
This patch adds a sanity check of the array index to fit in the array
size.Show less |
In the Linux kernel, the following vulnerability has been resolved:
cifs: Fix buffer overflow when parsing NFS reparse points
ReparseDataLength is sum of the InodeType size and DataBuffer size.
So to get DataBuffer siz...Show moreIn the Linux kernel, the following vulnerability has been resolved:
cifs: Fix buffer overflow when parsing NFS reparse points
ReparseDataLength is sum of the InodeType size and DataBuffer size.
So to get DataBuffer size it is needed to subtract InodeType's size from
ReparseDataLength.
Function cifs_strndup_from_utf16() is currentlly accessing buf->DataBuffer
at position after the end of the buffer because it does not subtract
InodeType size from the length. Fix this problem and correctly subtract
variable len.
Member InodeType is present only when reparse buffer is large enough. Check
for ReparseDataLength before accessing InodeType to prevent another invalid
memory access.
Major and minor rdev values are present also only when reparse buffer is
large enough. Check for reparse buffer size before calling reparse_mkdev().Show less |
In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: amdkfd_free_gtt_mem clear the correct pointer
Pass pointer reference to amdgpu_bo_unref to clear the correct pointer,
otherwise amdgpu_bo_...Show moreIn the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: amdkfd_free_gtt_mem clear the correct pointer
Pass pointer reference to amdgpu_bo_unref to clear the correct pointer,
otherwise amdgpu_bo_unref clear the local variable, the original pointer
not set to NULL, this could cause use-after-free bug.Show less |
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: fix double free issue during amdgpu module unload
Flexible endpoints use DIGs from available inflexible endpoints,
so only the encode...Show moreIn the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: fix double free issue during amdgpu module unload
Flexible endpoints use DIGs from available inflexible endpoints,
so only the encoders of inflexible links need to be freed.
Otherwise, a double free issue may occur when unloading the
amdgpu module.
[ 279.190523] RIP: 0010:__slab_free+0x152/0x2f0
[ 279.190577] Call Trace:
[ 279.190580] <TASK>
[ 279.190582] ? show_regs+0x69/0x80
[ 279.190590] ? die+0x3b/0x90
[ 279.190595] ? do_trap+0xc8/0xe0
[ 279.190601] ? do_error_trap+0x73/0xa0
[ 279.190605] ? __slab_free+0x152/0x2f0
[ 279.190609] ? exc_invalid_op+0x56/0x70
[ 279.190616] ? __slab_free+0x152/0x2f0
[ 279.190642] ? asm_exc_invalid_op+0x1f/0x30
[ 279.190648] ? dcn10_link_encoder_destroy+0x19/0x30 [amdgpu]
[ 279.191096] ? __slab_free+0x152/0x2f0
[ 279.191102] ? dcn10_link_encoder_destroy+0x19/0x30 [amdgpu]
[ 279.191469] kfree+0x260/0x2b0
[ 279.191474] dcn10_link_encoder_destroy+0x19/0x30 [amdgpu]
[ 279.191821] link_destroy+0xd7/0x130 [amdgpu]
[ 279.192248] dc_destruct+0x90/0x270 [amdgpu]
[ 279.192666] dc_destroy+0x19/0x40 [amdgpu]
[ 279.193020] amdgpu_dm_fini+0x16e/0x200 [amdgpu]
[ 279.193432] dm_hw_fini+0x26/0x40 [amdgpu]
[ 279.193795] amdgpu_device_fini_hw+0x24c/0x400 [amdgpu]
[ 279.194108] amdgpu_driver_unload_kms+0x4f/0x70 [amdgpu]
[ 279.194436] amdgpu_pci_remove+0x40/0x80 [amdgpu]
[ 279.194632] pci_device_remove+0x3a/0xa0
[ 279.194638] device_remove+0x40/0x70
[ 279.194642] device_release_driver_internal+0x1ad/0x210
[ 279.194647] driver_detach+0x4e/0xa0
[ 279.194650] bus_remove_driver+0x6f/0xf0
[ 279.194653] driver_unregister+0x33/0x60
[ 279.194657] pci_unregister_driver+0x44/0x90
[ 279.194662] amdgpu_exit+0x19/0x1f0 [amdgpu]
[ 279.194939] __do_sys_delete_module.isra.0+0x198/0x2f0
[ 279.194946] __x64_sys_delete_module+0x16/0x20
[ 279.194950] do_syscall_64+0x58/0x120
[ 279.194954] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 279.194980] </TASK>Show less |
In the Linux kernel, the following vulnerability has been resolved:
platform/x86: x86-android-tablets: Fix use after free on platform_device_register() errors
x86_android_tablet_remove() frees the pdevs[] array, so it...Show moreIn the Linux kernel, the following vulnerability has been resolved:
platform/x86: x86-android-tablets: Fix use after free on platform_device_register() errors
x86_android_tablet_remove() frees the pdevs[] array, so it should not
be used after calling x86_android_tablet_remove().
When platform_device_register() fails, store the pdevs[x] PTR_ERR() value
into the local ret variable before calling x86_android_tablet_remove()
to avoid using pdevs[] after it has been freed.Show less |
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: cancel dqi_sync_work before freeing oinfo
ocfs2_global_read_info() will initialize and schedule dqi_sync_work at the
end, if error occurs after...Show moreIn the Linux kernel, the following vulnerability has been resolved:
ocfs2: cancel dqi_sync_work before freeing oinfo
ocfs2_global_read_info() will initialize and schedule dqi_sync_work at the
end, if error occurs after successfully reading global quota, it will
trigger the following warning with CONFIG_DEBUG_OBJECTS_* enabled:
ODEBUG: free active (active state 0) object: 00000000d8b0ce28 object type: timer_list hint: qsync_work_fn+0x0/0x16c
This reports that there is an active delayed work when freeing oinfo in
error handling, so cancel dqi_sync_work first. BTW, return status instead
of -1 when .read_file_info fails.Show less |
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix timer use-after-free on failed mount
Syzbot has found an ODEBUG bug in ext4_fill_super
The del_timer_sync function cancels the s_err_report...Show moreIn the Linux kernel, the following vulnerability has been resolved:
ext4: fix timer use-after-free on failed mount
Syzbot has found an ODEBUG bug in ext4_fill_super
The del_timer_sync function cancels the s_err_report timer,
which reminds about filesystem errors daily. We should
guarantee the timer is no longer active before kfree(sbi).
When filesystem mounting fails, the flow goes to failed_mount3,
where an error occurs when ext4_stop_mmpd is called, causing
a read I/O failure. This triggers the ext4_handle_error function
that ultimately re-arms the timer,
leaving the s_err_report timer active before kfree(sbi) is called.
Fix the issue by canceling the s_err_report timer after calling ext4_stop_mmpd.Show less |
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: Fix uaf in l2cap_connect
[Syzbot reported]
BUG: KASAN: slab-use-after-free in l2cap_connect.constprop.0+0x10d8/0x1270 net/bluetooth/...Show moreIn the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: Fix uaf in l2cap_connect
[Syzbot reported]
BUG: KASAN: slab-use-after-free in l2cap_connect.constprop.0+0x10d8/0x1270 net/bluetooth/l2cap_core.c:3949
Read of size 8 at addr ffff8880241e9800 by task kworker/u9:0/54
CPU: 0 UID: 0 PID: 54 Comm: kworker/u9:0 Not tainted 6.11.0-rc6-syzkaller-00268-g788220eee30d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: hci2 hci_rx_work
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
print_address_description mm/kasan/report.c:377 [inline]
print_report+0xc3/0x620 mm/kasan/report.c:488
kasan_report+0xd9/0x110 mm/kasan/report.c:601
l2cap_connect.constprop.0+0x10d8/0x1270 net/bluetooth/l2cap_core.c:3949
l2cap_connect_req net/bluetooth/l2cap_core.c:4080 [inline]
l2cap_bredr_sig_cmd net/bluetooth/l2cap_core.c:4772 [inline]
l2cap_sig_channel net/bluetooth/l2cap_core.c:5543 [inline]
l2cap_recv_frame+0xf0b/0x8eb0 net/bluetooth/l2cap_core.c:6825
l2cap_recv_acldata+0x9b4/0xb70 net/bluetooth/l2cap_core.c:7514
hci_acldata_packet net/bluetooth/hci_core.c:3791 [inline]
hci_rx_work+0xaab/0x1610 net/bluetooth/hci_core.c:4028
process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
process_scheduled_works kernel/workqueue.c:3312 [inline]
worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
...
Freed by task 5245:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
poison_slab_object+0xf7/0x160 mm/kasan/common.c:240
__kasan_slab_free+0x32/0x50 mm/kasan/common.c:256
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2256 [inline]
slab_free mm/slub.c:4477 [inline]
kfree+0x12a/0x3b0 mm/slub.c:4598
l2cap_conn_free net/bluetooth/l2cap_core.c:1810 [inline]
kref_put include/linux/kref.h:65 [inline]
l2cap_conn_put net/bluetooth/l2cap_core.c:1822 [inline]
l2cap_conn_del+0x59d/0x730 net/bluetooth/l2cap_core.c:1802
l2cap_connect_cfm+0x9e6/0xf80 net/bluetooth/l2cap_core.c:7241
hci_connect_cfm include/net/bluetooth/hci_core.h:1960 [inline]
hci_conn_failed+0x1c3/0x370 net/bluetooth/hci_conn.c:1265
hci_abort_conn_sync+0x75a/0xb50 net/bluetooth/hci_sync.c:5583
abort_conn_sync+0x197/0x360 net/bluetooth/hci_conn.c:2917
hci_cmd_sync_work+0x1a4/0x410 net/bluetooth/hci_sync.c:328
process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
process_scheduled_works kernel/workqueue.c:3312 [inline]
worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244Show less |
In the Linux kernel, the following vulnerability has been resolved:
fbdev: pxafb: Fix possible use after free in pxafb_task()
In the pxafb_probe function, it calls the pxafb_init_fbinfo function,
after which &fbi->task...Show moreIn the Linux kernel, the following vulnerability has been resolved:
fbdev: pxafb: Fix possible use after free in pxafb_task()
In the pxafb_probe function, it calls the pxafb_init_fbinfo function,
after which &fbi->task is associated with pxafb_task. Moreover,
within this pxafb_init_fbinfo function, the pxafb_blank function
within the &pxafb_ops struct is capable of scheduling work.
If we remove the module which will call pxafb_remove to make cleanup,
it will call unregister_framebuffer function which can call
do_unregister_framebuffer to free fbi->fb through
put_fb_info(fb_info), while the work mentioned above will be used.
The sequence of operations that may lead to a UAF bug is as follows:
CPU0 CPU1
| pxafb_task
pxafb_remove |
unregister_framebuffer(info) |
do_unregister_framebuffer(fb_info) |
put_fb_info(fb_info) |
// free fbi->fb | set_ctrlr_state(fbi, state)
| __pxafb_lcd_power(fbi, 0)
| fbi->lcd_power(on, &fbi->fb.var)
| //use fbi->fb
Fix it by ensuring that the work is canceled before proceeding
with the cleanup in pxafb_remove.
Note that only root user can remove the driver at runtime.Show less |
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix index out of bounds in degamma hardware format translation
Fixes index out of bounds issue in
`cm_helper_translate_curve_to_degam...Show moreIn the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix index out of bounds in degamma hardware format translation
Fixes index out of bounds issue in
`cm_helper_translate_curve_to_degamma_hw_format` function. The issue
could occur when the index 'i' exceeds the number of transfer function
points (TRANSFER_FUNC_POINTS).
The fix adds a check to ensure 'i' is within bounds before accessing the
transfer function points. If 'i' is out of bounds the function returns
false to indicate an error.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:594 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.red' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:595 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.green' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:596 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.blue' 1025 <= s32maxShow less |
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:
========================================================...Show moreIn 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.Show less |
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_e...Show moreIn 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.Show less |
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...Show moreIn 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
[...]
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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...Show moreIn 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]Show less |
In the Linux kernel, the following vulnerability has been resolved:
firmware_loader: Block path traversal
Most firmware names are hardcoded strings, or are constructed from fairly
constrained format strings where the d...Show moreIn the Linux kernel, the following vulnerability has been resolved:
firmware_loader: Block path traversal
Most firmware names are hardcoded strings, or are constructed from fairly
constrained format strings where the dynamic parts are just some hex
numbers or such.
However, there are a couple codepaths in the kernel where firmware file
names contain string components that are passed through from a device or
semi-privileged userspace; the ones I could find (not counting interfaces
that require root privileges) are:
- lpfc_sli4_request_firmware_update() seems to construct the firmware
filename from "ModelName", a string that was previously parsed out of
some descriptor ("Vital Product Data") in lpfc_fill_vpd()
- nfp_net_fw_find() seems to construct a firmware filename from a model
name coming from nfp_hwinfo_lookup(pf->hwinfo, "nffw.partno"), which I
think parses some descriptor that was read from the device.
(But this case likely isn't exploitable because the format string looks
like "netronome/nic_%s", and there shouldn't be any *folders* starting
with "netronome/nic_". The previous case was different because there,
the "%s" is *at the start* of the format string.)
- module_flash_fw_schedule() is reachable from the
ETHTOOL_MSG_MODULE_FW_FLASH_ACT netlink command, which is marked as
GENL_UNS_ADMIN_PERM (meaning CAP_NET_ADMIN inside a user namespace is
enough to pass the privilege check), and takes a userspace-provided
firmware name.
(But I think to reach this case, you need to have CAP_NET_ADMIN over a
network namespace that a special kind of ethernet device is mapped into,
so I think this is not a viable attack path in practice.)
Fix it by rejecting any firmware names containing ".." path components.
For what it's worth, I went looking and haven't found any USB device
drivers that use the firmware loader dangerously.Show less |
In the Linux kernel, the following vulnerability has been resolved:
crypto: hisilicon/qm - inject error before stopping queue
The master ooo cannot be completely closed when the
accelerator core reports memory error. T...Show moreIn the Linux kernel, the following vulnerability has been resolved:
crypto: hisilicon/qm - inject error before stopping queue
The master ooo cannot be completely closed when the
accelerator core reports memory error. Therefore, the driver
needs to inject the qm error to close the master ooo. Currently,
the qm error is injected after stopping queue, memory may be
released immediately after stopping queue, causing the device to
access the released memory. Therefore, error is injected to close master
ooo before stopping queue to ensure that the device does not access
the released memory.Show less |
In the Linux kernel, the following vulnerability has been resolved:
drivers: media: dvb-frontends/rtl2832: fix an out-of-bounds write error
Ensure index in rtl2832_pid_filter does not exceed 31 to prevent
out-of-bounds...Show moreIn the Linux kernel, the following vulnerability has been resolved:
drivers: media: dvb-frontends/rtl2832: fix an out-of-bounds write error
Ensure index in rtl2832_pid_filter does not exceed 31 to prevent
out-of-bounds access.
dev->filters is a 32-bit value, so set_bit and clear_bit functions should
only operate on indices from 0 to 31. If index is 32, it will attempt to
access a non-existent 33rd bit, leading to out-of-bounds access.
Change the boundary check from index > 32 to index >= 32 to resolve this
issue.
[hverkuil: added fixes tag, rtl2830_pid_filter -> rtl2832_pid_filter in logmsg]Show less |