| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
x86/ioapic: Handle allocation failures gracefully
Breno observed panics when using failslab under certain conditions during
runtime:
can not alloc irq_pin_list (-1,0,20)
Kernel panic - not syncing: IO-APIC: failed to add irq-pin. Can not proceed
panic+0x4e9/0x590
mp_irqdomain_alloc+0x9ab/0xa80
irq_domain_alloc_irqs_locked+0x25d/0x8d0
__irq_domain_alloc_irqs+0x80/0x110
mp_map_pin_to_irq+0x645/0x890
acpi_register_gsi_ioapic+0xe6/0x150
hpet_open+0x313/0x480
That's a pointless panic which is a leftover of the historic IO/APIC code
which panic'ed during early boot when the interrupt allocation failed.
The only place which might justify panic is the PIT/HPET timer_check() code
which tries to figure out whether the timer interrupt is delivered through
the IO/APIC. But that code does not require to handle interrupt allocation
failures. If the interrupt cannot be allocated then timer delivery fails
and it either panics due to that or falls back to legacy mode.
Cure this by removing the panic wrapper around __add_pin_to_irq_node() and
making mp_irqdomain_alloc() aware of the failure condition and handle it as
any other failure in this function gracefully. |
| 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 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. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Add null check for top_pipe_to_program in commit_planes_for_stream
This commit addresses a null pointer dereference issue in the
`commit_planes_for_stream` function at line 4140. The issue could occur
when `top_pipe_to_program` is null.
The fix adds a check to ensure `top_pipe_to_program` is not null before
accessing its stream_res. This prevents a null pointer dereference.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc.c:4140 commit_planes_for_stream() error: we previously assumed 'top_pipe_to_program' could be null (see line 3906) |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Handle null 'stream_status' in 'planes_changed_for_existing_stream'
This commit adds a null check for 'stream_status' in the function
'planes_changed_for_existing_stream'. Previously, the code assumed
'stream_status' could be null, but did not handle the case where it was
actually null. This could lead to a null pointer dereference.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_resource.c:3784 planes_changed_for_existing_stream() error: we previously assumed 'stream_status' could be null (see line 3774) |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check null pointers before using dc->clk_mgr
[WHY & HOW]
dc->clk_mgr is null checked previously in the same function, indicating
it might be null.
Passing "dc" to "dc->hwss.apply_idle_power_optimizations", which
dereferences null "dc->clk_mgr". (The function pointer resolves to
"dcn35_apply_idle_power_optimizations".)
This fixes 1 FORWARD_NULL issue reported by Coverity. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Add null check for 'afb' in amdgpu_dm_plane_handle_cursor_update (v2)
This commit adds a null check for the 'afb' variable in the
amdgpu_dm_plane_handle_cursor_update function. Previously, 'afb' was
assumed to be null, but was used later in the code without a null check.
This could potentially lead to a null pointer dereference.
Changes since v1:
- Moved the null check for 'afb' to the line where 'afb' is used. (Alex)
Fixes the below:
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_plane.c:1298 amdgpu_dm_plane_handle_cursor_update() error: we previously assumed 'afb' could be null (see line 1252) |
| In the Linux kernel, the following vulnerability has been resolved:
jfs: Fix uaf in dbFreeBits
[syzbot reported]
==================================================================
BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:587 [inline]
BUG: KASAN: slab-use-after-free in __mutex_lock+0xfe/0xd70 kernel/locking/mutex.c:752
Read of size 8 at addr ffff8880229254b0 by task syz-executor357/5216
CPU: 0 UID: 0 PID: 5216 Comm: syz-executor357 Not tainted 6.11.0-rc3-syzkaller-00156-gd7a5aa4b3c00 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
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
__mutex_lock_common kernel/locking/mutex.c:587 [inline]
__mutex_lock+0xfe/0xd70 kernel/locking/mutex.c:752
dbFreeBits+0x7ea/0xd90 fs/jfs/jfs_dmap.c:2390
dbFreeDmap fs/jfs/jfs_dmap.c:2089 [inline]
dbFree+0x35b/0x680 fs/jfs/jfs_dmap.c:409
dbDiscardAG+0x8a9/0xa20 fs/jfs/jfs_dmap.c:1650
jfs_ioc_trim+0x433/0x670 fs/jfs/jfs_discard.c:100
jfs_ioctl+0x2d0/0x3e0 fs/jfs/ioctl.c:131
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
Freed by task 5218:
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+0xe0/0x150 mm/kasan/common.c:240
__kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2252 [inline]
slab_free mm/slub.c:4473 [inline]
kfree+0x149/0x360 mm/slub.c:4594
dbUnmount+0x11d/0x190 fs/jfs/jfs_dmap.c:278
jfs_mount_rw+0x4ac/0x6a0 fs/jfs/jfs_mount.c:247
jfs_remount+0x3d1/0x6b0 fs/jfs/super.c:454
reconfigure_super+0x445/0x880 fs/super.c:1083
vfs_cmd_reconfigure fs/fsopen.c:263 [inline]
vfs_fsconfig_locked fs/fsopen.c:292 [inline]
__do_sys_fsconfig fs/fsopen.c:473 [inline]
__se_sys_fsconfig+0xb6e/0xf80 fs/fsopen.c:345
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
[Analysis]
There are two paths (dbUnmount and jfs_ioc_trim) that generate race
condition when accessing bmap, which leads to the occurrence of uaf.
Use the lock s_umount to synchronize them, in order to avoid uaf caused
by race condition. |
| In the Linux kernel, the following vulnerability has been resolved:
jfs: check if leafidx greater than num leaves per dmap tree
syzbot report a out of bounds in dbSplit, it because dmt_leafidx greater
than num leaves per dmap tree, add a checking for dmt_leafidx in dbFindLeaf.
Shaggy:
Modified sanity check to apply to control pages as well as leaf pages. |
| In the Linux kernel, the following vulnerability has been resolved:
jfs: Fix uninit-value access of new_ea in ea_buffer
syzbot reports that lzo1x_1_do_compress is using uninit-value:
=====================================================
BUG: KMSAN: uninit-value in lzo1x_1_do_compress+0x19f9/0x2510 lib/lzo/lzo1x_compress.c:178
...
Uninit was stored to memory at:
ea_put fs/jfs/xattr.c:639 [inline]
...
Local variable ea_buf created at:
__jfs_setxattr+0x5d/0x1ae0 fs/jfs/xattr.c:662
__jfs_xattr_set+0xe6/0x1f0 fs/jfs/xattr.c:934
=====================================================
The reason is ea_buf->new_ea is not initialized properly.
Fix this by using memset to empty its content at the beginning
in ea_get(). |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check stream before comparing them
[WHAT & HOW]
amdgpu_dm can pass a null stream to dc_is_stream_unchanged. It is
necessary to check for null before dereferencing them.
This fixes 1 FORWARD_NULL issue reported by Coverity. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix index out of bounds in DCN30 degamma hardware format translation
This commit addresses a potential index out of bounds issue in the
`cm3_helper_translate_curve_to_degamma_hw_format` function in the DCN30
color management module. 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/dcn30/dcn30_cm_common.c:338 cm3_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.red' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn30/dcn30_cm_common.c:339 cm3_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.green' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn30/dcn30_cm_common.c:340 cm3_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.blue' 1025 <= s32max |
| 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_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 <= s32max |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Initialize get_bytes_per_element's default to 1
Variables, used as denominators and maybe not assigned to other values,
should not be 0. bytes_per_element_y & bytes_per_element_c are
initialized by get_bytes_per_element() which should never return 0.
This fixes 10 DIVIDE_BY_ZERO issues reported by Coverity. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/pm: ensure the fw_info is not null before using it
This resolves the dereference null return value warning
reported by Coverity. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: avoid use-after-free in ext4_ext_show_leaf()
In ext4_find_extent(), path may be freed by error or be reallocated, so
using a previously saved *ppath may have been freed and thus may trigger
use-after-free, as follows:
ext4_split_extent
path = *ppath;
ext4_split_extent_at(ppath)
path = ext4_find_extent(ppath)
ext4_split_extent_at(ppath)
// ext4_find_extent fails to free path
// but zeroout succeeds
ext4_ext_show_leaf(inode, path)
eh = path[depth].p_hdr
// path use-after-free !!!
Similar to ext4_split_extent_at(), we use *ppath directly as an input to
ext4_ext_show_leaf(). Fix a spelling error by the way.
Same problem in ext4_ext_handle_unwritten_extents(). Since 'path' is only
used in ext4_ext_show_leaf(), remove 'path' and use *ppath directly.
This issue is triggered only when EXT_DEBUG is defined and therefore does
not affect functionality. |
| In the Linux kernel, the following vulnerability has been resolved:
platform/x86: ISST: Fix the KASAN report slab-out-of-bounds bug
Attaching SST PCI device to VM causes "BUG: KASAN: slab-out-of-bounds".
kasan report:
[ 19.411889] ==================================================================
[ 19.413702] BUG: KASAN: slab-out-of-bounds in _isst_if_get_pci_dev+0x3d5/0x400 [isst_if_common]
[ 19.415634] Read of size 8 at addr ffff888829e65200 by task cpuhp/16/113
[ 19.417368]
[ 19.418627] CPU: 16 PID: 113 Comm: cpuhp/16 Tainted: G E 6.9.0 #10
[ 19.420435] Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference Platform, BIOS VMW201.00V.20192059.B64.2207280713 07/28/2022
[ 19.422687] Call Trace:
[ 19.424091] <TASK>
[ 19.425448] dump_stack_lvl+0x5d/0x80
[ 19.426963] ? _isst_if_get_pci_dev+0x3d5/0x400 [isst_if_common]
[ 19.428694] print_report+0x19d/0x52e
[ 19.430206] ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[ 19.431837] ? _isst_if_get_pci_dev+0x3d5/0x400 [isst_if_common]
[ 19.433539] kasan_report+0xf0/0x170
[ 19.435019] ? _isst_if_get_pci_dev+0x3d5/0x400 [isst_if_common]
[ 19.436709] _isst_if_get_pci_dev+0x3d5/0x400 [isst_if_common]
[ 19.438379] ? __pfx_sched_clock_cpu+0x10/0x10
[ 19.439910] isst_if_cpu_online+0x406/0x58f [isst_if_common]
[ 19.441573] ? __pfx_isst_if_cpu_online+0x10/0x10 [isst_if_common]
[ 19.443263] ? ttwu_queue_wakelist+0x2c1/0x360
[ 19.444797] cpuhp_invoke_callback+0x221/0xec0
[ 19.446337] cpuhp_thread_fun+0x21b/0x610
[ 19.447814] ? __pfx_cpuhp_thread_fun+0x10/0x10
[ 19.449354] smpboot_thread_fn+0x2e7/0x6e0
[ 19.450859] ? __pfx_smpboot_thread_fn+0x10/0x10
[ 19.452405] kthread+0x29c/0x350
[ 19.453817] ? __pfx_kthread+0x10/0x10
[ 19.455253] ret_from_fork+0x31/0x70
[ 19.456685] ? __pfx_kthread+0x10/0x10
[ 19.458114] ret_from_fork_asm+0x1a/0x30
[ 19.459573] </TASK>
[ 19.460853]
[ 19.462055] Allocated by task 1198:
[ 19.463410] kasan_save_stack+0x30/0x50
[ 19.464788] kasan_save_track+0x14/0x30
[ 19.466139] __kasan_kmalloc+0xaa/0xb0
[ 19.467465] __kmalloc+0x1cd/0x470
[ 19.468748] isst_if_cdev_register+0x1da/0x350 [isst_if_common]
[ 19.470233] isst_if_mbox_init+0x108/0xff0 [isst_if_mbox_msr]
[ 19.471670] do_one_initcall+0xa4/0x380
[ 19.472903] do_init_module+0x238/0x760
[ 19.474105] load_module+0x5239/0x6f00
[ 19.475285] init_module_from_file+0xd1/0x130
[ 19.476506] idempotent_init_module+0x23b/0x650
[ 19.477725] __x64_sys_finit_module+0xbe/0x130
[ 19.476506] idempotent_init_module+0x23b/0x650
[ 19.477725] __x64_sys_finit_module+0xbe/0x130
[ 19.478920] do_syscall_64+0x82/0x160
[ 19.480036] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 19.481292]
[ 19.482205] The buggy address belongs to the object at ffff888829e65000
which belongs to the cache kmalloc-512 of size 512
[ 19.484818] The buggy address is located 0 bytes to the right of
allocated 512-byte region [ffff888829e65000, ffff888829e65200)
[ 19.487447]
[ 19.488328] The buggy address belongs to the physical page:
[ 19.489569] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888829e60c00 pfn:0x829e60
[ 19.491140] head: order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
[ 19.492466] anon flags: 0x57ffffc0000840(slab|head|node=1|zone=2|lastcpupid=0x1fffff)
[ 19.493914] page_type: 0xffffffff()
[ 19.494988] raw: 0057ffffc0000840 ffff88810004cc80 0000000000000000 0000000000000001
[ 19.496451] raw: ffff888829e60c00 0000000080200018 00000001ffffffff 0000000000000000
[ 19.497906] head: 0057ffffc0000840 ffff88810004cc80 0000000000000000 0000000000000001
[ 19.499379] head: ffff888829e60c00 0000000080200018 00000001ffffffff 0000000000000000
[ 19.500844] head: 0057ffffc0000003 ffffea0020a79801 ffffea0020a79848 00000000ffffffff
[ 19.502316] head: 0000000800000000 0000000000000000 00000000ffffffff 0000000000000000
[ 19.503784] page dumped because: k
---truncated--- |
| 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. |
