In the Linux kernel, the following vulnerability has been resolved:
mm: vmalloc: ensure vmap_block is initialised before adding to queue
Commit 8c61291fd850 ("mm: fix incorrect vbq reference in
purge_fragmented_block") extended the 'vmap_block' structure to contain a
'cpu' field which is set at allocation time to the id of the initialising
CPU.
When a new 'vmap_block' is being instantiated by new_vmap_block(), the
partially initialised structure is added to the local 'vmap_block_queue'
xarray before the 'cpu' field has been initialised.  If another CPU is
concurrently walking the xarray (e.g.  via vm_unmap_aliases()), then it
may perform an out-of-bounds access to the remote queue thanks to an
uninitialised index.
This has been observed as UBSAN errors in Android:
 | Internal error: UBSAN: array index out of bounds: 00000000f2005512 [#1] PREEMPT SMP
 |
 | Call trace:
 |  purge_fragmented_block+0x204/0x21c
 |  _vm_unmap_aliases+0x170/0x378
 |  vm_unmap_aliases+0x1c/0x28
 |  change_memory_common+0x1dc/0x26c
 |  set_memory_ro+0x18/0x24
 |  module_enable_ro+0x98/0x238
 |  do_init_module+0x1b0/0x310
Move the initialisation of 'vb->cpu' in new_vmap_block() ahead of the
addition to the xarray.
                
            Metrics
Affected Vendors & Products
References
        History
                    Wed, 02 Oct 2024 14:45:00 +0000
| Type | Values Removed | Values Added | 
|---|---|---|
| First Time appeared | Linux Linux linux Kernel | |
| Weaknesses | CWE-129 | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.11:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.11:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.11:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.11:rc6:*:*:*:*:*:* | |
| Vendors & Products | Linux Linux linux Kernel | 
Sun, 29 Sep 2024 15:30:00 +0000
| Type | Values Removed | Values Added | 
|---|---|---|
| Metrics | ssvc 
 | 
Sat, 28 Sep 2024 01:15:00 +0000
| Type | Values Removed | Values Added | 
|---|---|---|
| References |  | |
| Metrics | threat_severity 
 | cvssV3_1 
 
 | 
Fri, 27 Sep 2024 12:45:00 +0000
| Type | Values Removed | Values Added | 
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: mm: vmalloc: ensure vmap_block is initialised before adding to queue Commit 8c61291fd850 ("mm: fix incorrect vbq reference in purge_fragmented_block") extended the 'vmap_block' structure to contain a 'cpu' field which is set at allocation time to the id of the initialising CPU. When a new 'vmap_block' is being instantiated by new_vmap_block(), the partially initialised structure is added to the local 'vmap_block_queue' xarray before the 'cpu' field has been initialised. If another CPU is concurrently walking the xarray (e.g. via vm_unmap_aliases()), then it may perform an out-of-bounds access to the remote queue thanks to an uninitialised index. This has been observed as UBSAN errors in Android: | Internal error: UBSAN: array index out of bounds: 00000000f2005512 [#1] PREEMPT SMP | | Call trace: | purge_fragmented_block+0x204/0x21c | _vm_unmap_aliases+0x170/0x378 | vm_unmap_aliases+0x1c/0x28 | change_memory_common+0x1dc/0x26c | set_memory_ro+0x18/0x24 | module_enable_ro+0x98/0x238 | do_init_module+0x1b0/0x310 Move the initialisation of 'vb->cpu' in new_vmap_block() ahead of the addition to the xarray. | |
| Title | mm: vmalloc: ensure vmap_block is initialised before adding to queue | |
| References |  | 
 MITRE
                        MITRE
                    Status: PUBLISHED
Assigner: Linux
Published: 2024-09-27T12:39:39.550Z
Updated: 2025-05-04T12:58:45.259Z
Reserved: 2024-09-11T15:12:18.290Z
Link: CVE-2024-46847
 Vulnrichment
                        Vulnrichment
                    Updated: 2024-09-29T13:58:56.460Z
 NVD
                        NVD
                    Status : Analyzed
Published: 2024-09-27T13:15:16.570
Modified: 2024-10-02T14:16:08.180
Link: CVE-2024-46847
 Redhat
                        Redhat