In the Linux kernel, the following vulnerability has been resolved: f2fs: fix NULL pointer dereference in f2fs_submit_page_write() BUG: kernel NULL pointer dereference, address: 0000000000000014 RIP: 0010:f2fs_submit_page_write+0x6cf/0x780 [f2fs] Call Trace: <TASK> ? show_regs+0x6e/0x80 ? __die+0x29/0x70 ? page_fault_oops+0x154/0x4a0 ? prb_read_valid+0x20/0x30 ? __irq_work_queue_local+0x39/0xd0 ? irq_work_queue+0x36/0x70 ? do_user_addr_fault+0x314/0x6c0 ? exc_page_fault+0x7d/0x190 ? asm_exc_page_fault+0x2b/0x30 ? f2fs_submit_page_write+0x6cf/0x780 [f2fs] ? f2fs_submit_page_write+0x736/0x780 [f2fs] do_write_page+0x50/0x170 [f2fs] f2fs_outplace_write_data+0x61/0xb0 [f2fs] f2fs_do_write_data_page+0x3f8/0x660 [f2fs] f2fs_write_single_data_page+0x5bb/0x7a0 [f2fs] f2fs_write_cache_pages+0x3da/0xbe0 [f2fs] ... It is possible that other threads have added this fio to io->bio and submitted the io->bio before entering f2fs_submit_page_write(). At this point io->bio = NULL. If is_end_zone_blkaddr(sbi, fio->new_blkaddr) of this fio is true, then an NULL pointer dereference error occurs at bio_get(io->bio). The original code for determining zone end was after "out:", which would have missed some fio who is zone end. I've moved this code before "skip:" to make sure it's done for each fio.
| 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 |
f2fs: fix NULL pointer dereference in f2fs_submit_page_write()