In the Linux kernel, the following vulnerability has been resolved:
erofs: fix inline data read failure for ztailpacking pclusters
Compressed folios for ztailpacking pclusters must be valid before adding
these pclusters to I/O chains. Otherwise, z_erofs_decompress_pcluster()
may assume they are already valid and then trigger a NULL pointer
dereference.
It is somewhat hard to reproduce because the inline data is in the same
block as the tail of the compressed indexes, which are usually read just
before. However, it may still happen if a fatal signal arrives while
read_mapping_folio() is running, as shown below:
erofs: (device dm-1): z_erofs_pcluster_begin: failed to get inline data -4
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
...
pc : z_erofs_decompress_queue+0x4c8/0xa14
lr : z_erofs_decompress_queue+0x160/0xa14
sp : ffffffc08b3eb3a0
x29: ffffffc08b3eb570 x28: ffffffc08b3eb418 x27: 0000000000001000
x26: ffffff8086ebdbb8 x25: ffffff8086ebdbb8 x24: 0000000000000001
x23: 0000000000000008 x22: 00000000fffffffb x21: dead000000000700
x20: 00000000000015e7 x19: ffffff808babb400 x18: ffffffc089edc098
x17: 00000000c006287d x16: 00000000c006287d x15: 0000000000000004
x14: ffffff80ba8f8000 x13: 0000000000000004 x12: 00000006589a77c9
x11: 0000000000000015 x10: 0000000000000000 x9 : 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000040 x4 : ffffffffffffffe0 x3 : 0000000000000020
x2 : 0000000000000008 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
z_erofs_decompress_queue+0x4c8/0xa14
z_erofs_runqueue+0x908/0x97c
z_erofs_read_folio+0x128/0x228
filemap_read_folio+0x68/0x128
filemap_get_pages+0x44c/0x8b4
filemap_read+0x12c/0x5b8
generic_file_read_iter+0x4c/0x15c
do_iter_readv_writev+0x188/0x1e0
vfs_iter_read+0xac/0x1a4
backing_file_read_iter+0x170/0x34c
ovl_read_iter+0xf0/0x140
vfs_read+0x28c/0x344
ksys_read+0x80/0xf0
__arm64_sys_read+0x24/0x34
invoke_syscall+0x60/0x114
el0_svc_common+0x88/0xe4
do_el0_svc+0x24/0x30
el0_svc+0x40/0xa8
el0t_64_sync_handler+0x70/0xbc
el0t_64_sync+0x1bc/0x1c0
Fix this by reading the inline data before allocating and adding
the pclusters to the I/O chains.
erofs: fix inline data read failure for ztailpacking pclusters
Compressed folios for ztailpacking pclusters must be valid before adding
these pclusters to I/O chains. Otherwise, z_erofs_decompress_pcluster()
may assume they are already valid and then trigger a NULL pointer
dereference.
It is somewhat hard to reproduce because the inline data is in the same
block as the tail of the compressed indexes, which are usually read just
before. However, it may still happen if a fatal signal arrives while
read_mapping_folio() is running, as shown below:
erofs: (device dm-1): z_erofs_pcluster_begin: failed to get inline data -4
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
...
pc : z_erofs_decompress_queue+0x4c8/0xa14
lr : z_erofs_decompress_queue+0x160/0xa14
sp : ffffffc08b3eb3a0
x29: ffffffc08b3eb570 x28: ffffffc08b3eb418 x27: 0000000000001000
x26: ffffff8086ebdbb8 x25: ffffff8086ebdbb8 x24: 0000000000000001
x23: 0000000000000008 x22: 00000000fffffffb x21: dead000000000700
x20: 00000000000015e7 x19: ffffff808babb400 x18: ffffffc089edc098
x17: 00000000c006287d x16: 00000000c006287d x15: 0000000000000004
x14: ffffff80ba8f8000 x13: 0000000000000004 x12: 00000006589a77c9
x11: 0000000000000015 x10: 0000000000000000 x9 : 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000040 x4 : ffffffffffffffe0 x3 : 0000000000000020
x2 : 0000000000000008 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
z_erofs_decompress_queue+0x4c8/0xa14
z_erofs_runqueue+0x908/0x97c
z_erofs_read_folio+0x128/0x228
filemap_read_folio+0x68/0x128
filemap_get_pages+0x44c/0x8b4
filemap_read+0x12c/0x5b8
generic_file_read_iter+0x4c/0x15c
do_iter_readv_writev+0x188/0x1e0
vfs_iter_read+0xac/0x1a4
backing_file_read_iter+0x170/0x34c
ovl_read_iter+0xf0/0x140
vfs_read+0x28c/0x344
ksys_read+0x80/0xf0
__arm64_sys_read+0x24/0x34
invoke_syscall+0x60/0x114
el0_svc_common+0x88/0xe4
do_el0_svc+0x24/0x30
el0_svc+0x40/0xa8
el0t_64_sync_handler+0x70/0xbc
el0t_64_sync+0x1bc/0x1c0
Fix this by reading the inline data before allocating and adding
the pclusters to the I/O chains.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||||||||
| Linux | Linux | affected |
|
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Fixes
Solution
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Workaround
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References
History
Wed, 27 May 2026 14:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: erofs: fix inline data read failure for ztailpacking pclusters Compressed folios for ztailpacking pclusters must be valid before adding these pclusters to I/O chains. Otherwise, z_erofs_decompress_pcluster() may assume they are already valid and then trigger a NULL pointer dereference. It is somewhat hard to reproduce because the inline data is in the same block as the tail of the compressed indexes, which are usually read just before. However, it may still happen if a fatal signal arrives while read_mapping_folio() is running, as shown below: erofs: (device dm-1): z_erofs_pcluster_begin: failed to get inline data -4 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 ... pc : z_erofs_decompress_queue+0x4c8/0xa14 lr : z_erofs_decompress_queue+0x160/0xa14 sp : ffffffc08b3eb3a0 x29: ffffffc08b3eb570 x28: ffffffc08b3eb418 x27: 0000000000001000 x26: ffffff8086ebdbb8 x25: ffffff8086ebdbb8 x24: 0000000000000001 x23: 0000000000000008 x22: 00000000fffffffb x21: dead000000000700 x20: 00000000000015e7 x19: ffffff808babb400 x18: ffffffc089edc098 x17: 00000000c006287d x16: 00000000c006287d x15: 0000000000000004 x14: ffffff80ba8f8000 x13: 0000000000000004 x12: 00000006589a77c9 x11: 0000000000000015 x10: 0000000000000000 x9 : 0000000000000000 x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f x5 : 0000000000000040 x4 : ffffffffffffffe0 x3 : 0000000000000020 x2 : 0000000000000008 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: z_erofs_decompress_queue+0x4c8/0xa14 z_erofs_runqueue+0x908/0x97c z_erofs_read_folio+0x128/0x228 filemap_read_folio+0x68/0x128 filemap_get_pages+0x44c/0x8b4 filemap_read+0x12c/0x5b8 generic_file_read_iter+0x4c/0x15c do_iter_readv_writev+0x188/0x1e0 vfs_iter_read+0xac/0x1a4 backing_file_read_iter+0x170/0x34c ovl_read_iter+0xf0/0x140 vfs_read+0x28c/0x344 ksys_read+0x80/0xf0 __arm64_sys_read+0x24/0x34 invoke_syscall+0x60/0x114 el0_svc_common+0x88/0xe4 do_el0_svc+0x24/0x30 el0_svc+0x40/0xa8 el0t_64_sync_handler+0x70/0xbc el0t_64_sync+0x1bc/0x1c0 Fix this by reading the inline data before allocating and adding the pclusters to the I/O chains. | |
| Title | erofs: fix inline data read failure for ztailpacking pclusters | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-27T12:17:58.764Z
Reserved: 2026-05-13T15:03:33.087Z
Link: CVE-2026-45943
Vulnrichment
No data.
NVD
Status : Awaiting Analysis
Published: 2026-05-27T14:17:10.557
Modified: 2026-05-27T14:48:03.013
Link: CVE-2026-45943
Redhat
No data.
OpenCVE Enrichment
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Weaknesses
No weakness.