Title: kernel de Linux
Description: En el kernel de Linux, se resolvió la siguiente vulnerabilidad: ext4: verificación de integridad del puntero NULL después de ext4_force_shutdown Caso de prueba: 2 subprocesos escriben datos breves en línea en un archivo. En ext4_page_mkwrite se convierten los datos en línea resultantes. El manejo de ext4_grp_locked_error con la descripción "mapa de bits de bloque y descriptor de bg inconsistentes: clústeres libres X vs Y" llama a ext4_force_shutdown. La conversión borra EXT4_STATE_MAY_INLINE_DATA pero falla para ext4_destroy_inline_data_nolock y ext4_mark_iloc_dirty debido a ext4_forced_shutdown. La restauración de datos en línea falla por el mismo motivo al no configurar EXT4_STATE_MAY_INLINE_DATA. Sin el indicador establecido, una ruta de proceso normal en ext4_da_write_end sigue intentando eliminar la referencia al puntero privado de la página que no se ha configurado. La solución llama al retorno anticipado con el error -EIO y el puntero a privado será NULL. Informe de falla de muestra: No se puede manejar la solicitud de paginación del kernel en la dirección virtual dfff800000000004 KASAN: null-ptr-deref en el rango [0x000000000000020-0x00000000000000027] Información de cancelación de memoria: ESR = 0x0000000096000005 EC = 0x25: DABT (actual EL), IL = 32 bits CONJUNTO = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: error de traducción de nivel 1 Información de cancelación de datos: ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 dirección [dfff800000000004] entre los rangos de direcciones del usuario y del kernel Error interno: Ups: 0000000096000005 [#1] Módulos SMP PREEMPT vinculados en: CPU: 1 PID: 20274 Comm: syz-executor185 No está contaminado 6.9.0-rc7-syzkaller-gfda5695d692c #0 Nombre del hardware: Google Google Compute Engine/Google Compute Engine, BIOS Google 27/03/2024 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT - SSBS BTYPE=--) pc: __block_commit_write+0x64/0x2b0 fs/buffer.c:2167 lr: __block_commit_write+0x3c/0x2b0 fs/buffer.c:2160 sp: ffff8000a1957600 x29: ffff8000a1957610 x28: 00000000 x27: ffff0000e30e34b0 x26: 0000000000000000 x25 : dfff800000000000 x24: dfff800000000000 x23: fffffdffc397c9e0 x22: 0000000000000020 x21: 00000000000000020 x20: 0000000000000040 x19: ffc397c9c0 x18: 1fffe000367bd196 x17: ffff80008eead000 x16: ffff80008ae89e3c x15: 00000000200000c0 x14: 1fffe0001cbe4e04 x13: 00000000000000000 x 12: 0000000000000000 x11: 0000000000000001 x10: 0000000000ff0100 x9: 0000000000000000 x8: 0000000000000004 x7: 0000000000000000 x6: 0000000000000000 x5: fffffdffc397c9c0 x4: 00000000000000020 x3: 0000000000000020 x2: 000 0000000000040 x1: 0000000000000020 x0: fffffdffc397c9c0 Rastreo de llamadas: __block_commit_write+0x64/0x2b0 fs/buffer.c:2167 block_write_end+0xb4/0x104 fs/buffer .c:2253 ext4_da_do_write_end fs/ext4/inode.c:2955 [en línea] ext4_da_write_end+0x2c4/0xa40 fs/ext4/inode.c:3028 generic_perform_write+0x394/0x588 mm/filemap.c:3985 ext4_buffered_write_iter+0x2c0/0 x4ecfs/ ext4/file.c:299 ext4_file_write_iter+0x188/0x1780 call_write_iter include/linux/fs.h:2110 [en línea] new_sync_write fs/read_write.c:497 [en línea] vfs_write+0x968/0xc3c fs/read_write.c:590 ksys_write+ 0x15c/0x26c fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [en línea] __se_sys_write fs/read_write.c:652 [en línea] __arm64_sys_write+0x7c/0x90 fs/read_write.c:652 __invoke_syscall arch/arm64/ núcleo /syscall.c:34 [en línea] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133 do_el0_svc+0x48/0x58 arch/arm64/ kernel/syscall.c:152 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/ arm64/kernel/entry.S:598 Código: 97f85911 f94002da 91008356 d343fec8 (38796908) ---[ end trace 00000000000000000 ]--------- TRUNCADO ----------

OR
     
          *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 from (excluding) 6.10.5
          *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (excluding) 6.6.47

NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

NIST CWE-476

In the Linux kernel, the following vulnerability has been resolved:

ext4: sanity check for NULL pointer after ext4_force_shutdown

Test case: 2 threads write short inline data to a file.
In ext4_page_mkwrite the resulting inline data is converted.
Handling ext4_grp_locked_error with description "block bitmap
and bg descriptor inconsistent: X vs Y free clusters" calls
ext4_force_shutdown. The conversion clears
EXT4_STATE_MAY_INLINE_DATA but fails for
ext4_destroy_inline_data_nolock and ext4_mark_iloc_dirty due
to ext4_forced_shutdown. The restoration of inline data fails
for the same reason not setting EXT4_STATE_MAY_INLINE_DATA.
Without the flag set a regular process path in ext4_da_write_end
follows trying to dereference page folio private pointer that has
not been set. The fix calls early return with -EIO error shall the
pointer to private be NULL.

Sample crash report:

Unable to handle kernel paging request at virtual address dfff800000000004
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
Mem abort info:
  ESR = 0x0000000096000005
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x05: level 1 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
  CM = 0, WnR = 0, TnD = 0, TagAccess = 0
  GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[dfff800000000004] address between user and kernel address ranges
Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 20274 Comm: syz-executor185 Not tainted 6.9.0-rc7-syzkaller-gfda5695d692c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __block_commit_write+0x64/0x2b0 fs/buffer.c:2167
lr : __block_commit_write+0x3c/0x2b0 fs/buffer.c:2160
sp : ffff8000a1957600
x29: ffff8000a1957610 x28: dfff800000000000 x27: ffff0000e30e34b0
x26: 0000000000000000 x25: dfff800000000000 x24: dfff800000000000
x23: fffffdffc397c9e0 x22: 0000000000000020 x21: 0000000000000020
x20: 0000000000000040 x19: fffffdffc397c9c0 x18: 1fffe000367bd196
x17: ffff80008eead000 x16: ffff80008ae89e3c x15: 00000000200000c0
x14: 1fffe0001cbe4e04 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000001 x10: 0000000000ff0100 x9 : 0000000000000000
x8 : 0000000000000004 x7 : 0000000000000000 x6 : 0000000000000000
x5 : fffffdffc397c9c0 x4 : 0000000000000020 x3 : 0000000000000020
x2 : 0000000000000040 x1 : 0000000000000020 x0 : fffffdffc397c9c0
Call trace:
 __block_commit_write+0x64/0x2b0 fs/buffer.c:2167
 block_write_end+0xb4/0x104 fs/buffer.c:2253
 ext4_da_do_write_end fs/ext4/inode.c:2955 [inline]
 ext4_da_write_end+0x2c4/0xa40 fs/ext4/inode.c:3028
 generic_perform_write+0x394/0x588 mm/filemap.c:3985
 ext4_buffered_write_iter+0x2c0/0x4ec fs/ext4/file.c:299
 ext4_file_write_iter+0x188/0x1780
 call_write_iter include/linux/fs.h:2110 [inline]
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0x968/0xc3c fs/read_write.c:590
 ksys_write+0x15c/0x26c fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:652
 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598
Code: 97f85911 f94002da 91008356 d343fec8 (38796908)
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	97f85911 	bl	0xffffffffffe16444
   4:	f94002da 	ldr	x26, [x22]
   8:	91008356 	add	x22, x26, #0x20
   c:	d343fec8 	lsr	x8, x22, #3
* 10:	38796908 	ldrb	w8, [x8, x25] <-- trapping instruction

Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.

kernel.org https://git.kernel.org/stable/c/3f6bbe6e07e5239294ecc3d2efa70d1f98aed52e

kernel.org https://git.kernel.org/stable/c/83f4414b8f84249d538905825b088ff3ae555652

kernel.org https://git.kernel.org/stable/c/f619876ccbfd329ae785fe5d3289b9dcd6eb5901