"value":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix off by one issue in alloc_flex_gd()\n\nWesley reported an issue:\n\n==================================================================\nEXT4-fs (dm-5): resizing filesystem from 7168 to 786432 blocks\n------------[ cut here ]------------\nkernel BUG at fs/ext4/resize.c:324!\nCPU: 9 UID: 0 PID: 3576 Comm: resize2fs Not tainted 6.11.0+ #27\nRIP: 0010:ext4_resize_fs+0x1212/0x12d0\nCall Trace:\n __ext4_ioctl+0x4e0/0x1800\n ext4_ioctl+0x12/0x20\n __x64_sys_ioctl+0x99/0xd0\n x64_sys_call+0x1206/0x20d0\n do_syscall_64+0x72/0x110\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n==================================================================\n\nWhile reviewing the patch, Honza found that when adjusting resize_bg in\nalloc_flex_gd(), it was possible for flex_gd->resize_bg to be bigger than\nflexbg_size.\n\nThe reproduction of the problem requires the following:\n\n o_group = flexbg_size * 2 * n;\n o_size = (o_group + 1) * group_size;\n n_group: [o_group + flexbg_size, o_group + flexbg_size * 2)\n o_size = (n_group + 1) * group_size;\n\nTake n=0,flexbg_size=16 as an example:\n\n last:15\n|o---------------|--------------n-|\no_group:0 resize to n_group:30\n\nThe corresponding reproducer is:\n\nimg=test.img\nrm -f $img\ntruncate -s 600M $img\nmkfs.ext4 -F $img -b 1024 -G 16 8M\ndev=`losetup -f --show $img`\nmkdir -p /tmp/test\nmount $dev /tmp/test\nresize2fs $dev 248M\n\nDelete the problematic plus 1 to fix the issue, and add a WARN_ON_ONCE()\nto prevent the issue from happening again.\n\n[ Note: another reproucer which this commit fixes is:\n\n img=test.img\n rm -f $img\n truncate -s 25MiB $img\n mkfs.ext4 -b 4096 -E nodiscard,lazy_itable_init=0,lazy_journal_init=0 $img\n truncate -s 3GiB $img\n dev=`losetup -f --show $img`\n mkdir -p /tmp/test\n mount $dev /tmp/test\n resize2fs $dev 3G\n umount $dev\n losetup -d $dev\n\n -- TYT ]"
"value":"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ext4: correcci\u00f3n de un problema en alloc_flex_gd() Wesley inform\u00f3 de un problema: ======================================================================= EXT4-fs (dm-5): cambio de tama\u00f1o del sistema de archivos de 7168 a 786432 bloques ------------[ corte aqu\u00ed ]------------ \u00a1ERROR 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 m\u00e1s 1 para solucionar el problema y agregue un WARN_ON_ONCE() para evitar que el problema vuelva a ocurrir. [ Nota: otro reprocesador que esta confirmaci\u00f3n 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 ]"
