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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
88e0ad40d08a73a74c597e69f4cd2d1fba3838b5 to < 1b2770e27d6d952f491bb362b657e5b2713c3efdaffected8c61291fd8500e3b35c7ec0c781b273d8cc96cde to < 6cf74e0e5e3ab5d5c9defb4c73dad54d52224671affected8c61291fd8500e3b35c7ec0c781b273d8cc96cde to < 3e3de7947c751509027d26b679ecd243bc9db255affected9983b81579be3403f5cc44b11f66c6c8bea6547faffected6.6.37 to < 6.6.51affected6.9.8 to < 6.10affected
Linux Linux
Default version status: affected
6.10affected0 to < 6.10unaffected6.6.51 to ≤ 6.6.*unaffected6.10.10 to ≤ 6.10.*unaffected6.11 to ≤ *unaffected