In the Linux kernel, the following vulnerability has been resolved: mm/gup: fix gup_pud_range() for dax For dax pud, pud_huge() returns true on x86. So the function works as long as hugetlb is configured. However, dax doesn't depend on hugetlb. Commit 414fd080d125 ("mm/gup: fix gup_pmd_range() for dax") fixed devmap-backed huge PMDs, but missed devmap-backed huge PUDs. Fix this as well. This fixes the below kernel panic: general protection fault, probably for non-canonical address 0x69e7c000cc478: 0000 [#1] SMP < snip > Call Trace: <TASK> get_user_pages_fast+0x1f/0x40 iov_iter_get_pages+0xc6/0x3b0 ? mempool_alloc+0x5d/0x170 bio_iov_iter_get_pages+0x82/0x4e0 ? bvec_alloc+0x91/0xc0 ? bio_alloc_bioset+0x19a/0x2a0 blkdev_direct_IO+0x282/0x480 ? __io_complete_rw_common+0xc0/0xc0 ? filemap_range_has_page+0x82/0xc0 generic_file_direct_write+0x9d/0x1a0 ? inode_update_time+0x24/0x30 __generic_file_write_iter+0xbd/0x1e0 blkdev_write_iter+0xb4/0x150 ? io_import_iovec+0x8d/0x340 io_write+0xf9/0x300 io_issue_sqe+0x3c3/0x1d30 ? sysvec_reschedule_ipi+0x6c/0x80 __io_queue_sqe+0x33/0x240 ? fget+0x76/0xa0 io_submit_sqes+0xe6a/0x18d0 ? __fget_light+0xd1/0x100 __x64_sys_io_uring_enter+0x199/0x880 ? __context_tracking_enter+0x1f/0x70 ? irqentry_exit_to_user_mode+0x24/0x30 ? irqentry_exit+0x1d/0x30 ? __context_tracking_exit+0xe/0x70 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fc97c11a7be < snip > </TASK> ---[ end trace 48b2e0e67debcaeb ]--- RIP: 0010:internal_get_user_pages_fast+0x340/0x990 < snip > Kernel panic - not syncing: Fatal exception Kernel Offset: disabled
| Métrique | Valeur | Interprétation |
|---|---|---|
|
AV (Vecteur d'Attaque)
Attack Vector
|
Local (L)
|
Exploit nécessite un accès local au système |
|
AC (Complexité d'Attaque)
Attack Complexity
|
Low (L)
|
Peu de conditions requises pour exploiter |
|
PR (Privilèges Requis)
Privileges Required
|
Low (L)
|
Authentifié avec compte utilisateur basique |
|
UI (Interaction Utilisateur)
User Interaction
|
None (N)
|
Aucune interaction utilisateur nécessaire |
|
S (Périmètre)
Scope
|
Unchanged (U)
|
Impact reste dans le périmètre du composant compromis |
|
C (Impact Confidentialité)
Confidentiality Impact
|
None (N)
|
Aucune divulgation d'informations |
|
I (Impact Intégrité)
Integrity Impact
|
None (N)
|
Aucune modification de données possible |
|
A (Impact Disponibilité)
Availability Impact
|
High (H)
|
Interruption totale du service possible |
mm/gup: fix gup_pud_range() for dax