CVE-2024-49880

In the Linux kernel, the following vulnerability has been resolved: ext4: fix off by one issue in alloc_flex_gd() Wesley reported an issue: ================================================================== EXT4-fs (dm-5): resizing filesystem from 7168 to 786432 blocks ------------[ cut here ]------------ kernel BUG at fs/ext4/resize.c:324! CPU: 9 UID: 0 PID: 3576 Comm: resize2fs Not tainted 6.11.0+ #27 RIP: 0010:ext4_resize_fs+0x1212/0x12d0 Call Trace: __ext4_ioctl+0x4e0/0x1800 ext4_ioctl+0x12/0x20 __x64_sys_ioctl+0x99/0xd0 x64_sys_call+0x1206/0x20d0 do_syscall_64+0x72/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e ================================================================== While reviewing the patch, Honza found that when adjusting resize_bg in alloc_flex_gd(), it was possible for flex_gd->resize_bg to be bigger than flexbg_size. The reproduction of the problem requires the following: o_group = flexbg_size * 2 * n; o_size = (o_group + 1) * group_size; n_group: [o_group + flexbg_size, o_group + flexbg_size * 2) o_size = (n_group + 1) * group_size; Take n=0,flexbg_size=16 as an example: last:15 |o---------------|--------------n-| o_group:0 resize to n_group:30 The corresponding reproducer is: img=test.img rm -f $img truncate -s 600M $img mkfs.ext4 -F $img -b 1024 -G 16 8M dev=`losetup -f --show $img` mkdir -p /tmp/test mount $dev /tmp/test resize2fs $dev 248M Delete the problematic plus 1 to fix the issue, and add a WARN_ON_ONCE() to prevent the issue from happening again. [ Note: another reproucer which this commit fixes is: img=test.img rm -f $img truncate -s 25MiB $img mkfs.ext4 -b 4096 -E nodiscard,lazy_itable_init=0,lazy_journal_init=0 $img truncate -s 3GiB $img dev=`losetup -f --show $img` mkdir -p /tmp/test mount $dev /tmp/test resize2fs $dev 3G umount $dev losetup -d $dev -- TYT ]
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:*

History

25 Oct 2024, 14:42

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/0d80d2b8bf613398baf7185009e35f9d0459ecb0 - () https://git.kernel.org/stable/c/0d80d2b8bf613398baf7185009e35f9d0459ecb0 - Patch
References () https://git.kernel.org/stable/c/6121258c2b33ceac3d21f6a221452692c465df88 - () https://git.kernel.org/stable/c/6121258c2b33ceac3d21f6a221452692c465df88 - Patch
References () https://git.kernel.org/stable/c/acb559d6826116cc113598640d105094620c2526 - () https://git.kernel.org/stable/c/acb559d6826116cc113598640d105094620c2526 - Patch
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:*
CWE CWE-193
First Time Linux linux Kernel
Linux
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.8

23 Oct 2024, 15:13

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ext4: corrección de un problema en alloc_flex_gd() Wesley informó de un problema: ======================================================================= EXT4-fs (dm-5): cambio de tamaño del sistema de archivos de 7168 a 786432 bloques ------------[ corte aquí ]------------ ¡ERROR del kernel en fs/ext4/resize.c:324! CPU: 9 UID: 0 PID: 3576 Comm: resize2fs No contaminado 6.11.0+ #27 RIP: 0010:ext4_resize_fs+0x1212/0x12d0 Rastreo de llamadas: __ext4_ioctl+0x4e0/0x1800 ext4_ioctl+0x12/0x20 __x64_sys_ioctl+0x99/0xd0 x64_sys_call+0x1206/0x20d0 do_syscall_64+0x72/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e == ... Tome n=0,flexbg_size=16 como ejemplo: last:15 |o---------------|--------------n-| o_group:0 redimensionar a n_group:30 El reproductor correspondiente es: img=test.img rm -f $img truncate -s 600M $img mkfs.ext4 -F $img -b 1024 -G 16 8M dev=`losetup -f --show $img` mkdir -p /tmp/test mount $dev /tmp/test resize2fs $dev 248M Elimine el problema más 1 para solucionar el problema y agregue un WARN_ON_ONCE() para evitar que el problema vuelva a ocurrir. [ Nota: otro reprocesador que esta confirmación corrige es: img=test.img rm -f $img truncate -s 25MiB $img mkfs.ext4 -b 4096 -E nodiscard,lazy_itable_init=0,lazy_journal_init=0 $img truncate -s 3GiB $img dev=`losetup -f --show $img` mkdir -p /tmp/test mount $dev /tmp/test resize2fs $dev 3G umount $dev losetup -d $dev -- TYT ]

21 Oct 2024, 18:15

Type Values Removed Values Added
New CVE

Information

Published : 2024-10-21 18:15

Updated : 2024-10-25 14:42


NVD link : CVE-2024-49880

Mitre link : CVE-2024-49880

CVE.ORG link : CVE-2024-49880


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-193

Off-by-one Error