{"id":"DEBIAN-CVE-2023-53323","details":"In the Linux kernel, the following vulnerability has been resolved:  ext2/dax: Fix ext2_setsize when len is page aligned  PAGE_ALIGN(x) macro gives the next highest value which is multiple of pagesize. But if x is already page aligned then it simply returns x. So, if x passed is 0 in dax_zero_range() function, that means the length gets passed as 0 to -\u003eiomap_begin().  In ext2 it then calls ext2_get_blocks -\u003e max_blocks as 0 and hits bug_on here in ext2_get_blocks(). \tBUG_ON(maxblocks == 0);  Instead we should be calling dax_truncate_page() here which takes care of it. i.e. it only calls dax_zero_range if the offset is not page/block aligned.  This can be easily triggered with following on fsdax mounted pmem device.  dd if=/dev/zero of=file count=1 bs=512 truncate -s 0 file  [79.525838] EXT2-fs (pmem0): DAX enabled. Warning: EXPERIMENTAL, use at your own risk [79.529376] ext2 filesystem being mounted at /mnt1/test supports timestamps until 2038 (0x7fffffff) [93.793207] ------------[ cut here ]------------ [93.795102] kernel BUG at fs/ext2/inode.c:637! [93.796904] invalid opcode: 0000 [#1] PREEMPT SMP PTI [93.798659] CPU: 0 PID: 1192 Comm: truncate Not tainted 6.3.0-rc2-xfstests-00056-g131086faa369 #139 [93.806459] RIP: 0010:ext2_get_blocks.constprop.0+0x524/0x610 \u003c...\u003e [93.835298] Call Trace: [93.836253]  \u003cTASK\u003e [93.837103]  ? lock_acquire+0xf8/0x110 [93.838479]  ? d_lookup+0x69/0xd0 [93.839779]  ext2_iomap_begin+0xa7/0x1c0 [93.841154]  iomap_iter+0xc7/0x150 [93.842425]  dax_zero_range+0x6e/0xa0 [93.843813]  ext2_setsize+0x176/0x1b0 [93.845164]  ext2_setattr+0x151/0x200 [93.846467]  notify_change+0x341/0x4e0 [93.847805]  ? lock_acquire+0xf8/0x110 [93.849143]  ? do_truncate+0x74/0xe0 [93.850452]  ? do_truncate+0x84/0xe0 [93.851739]  do_truncate+0x84/0xe0 [93.852974]  do_sys_ftruncate+0x2b4/0x2f0 [93.854404]  do_syscall_64+0x3f/0x90 [93.855789]  entry_SYSCALL_64_after_hwframe+0x72/0xdc","modified":"2026-09-15T09:02:54.091457519Z","published":"2025-09-16T17:15:38.410Z","upstream":["CVE-2023-53323"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2023-53323"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.52-1"}]}],"versions":["6.1.27-1","6.1.37-1","6.1.38-1","6.1.38-2","6.1.38-2~bpo11+1","6.1.38-3","6.1.38-4","6.1.38-4~bpo11+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-53323.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.4.11-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-53323.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.4.11-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-53323.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}