CVE-2025-40054
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix UAF issue in f2fs_merge_page_bio() As JY reported in bugzilla [1], Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 pc : [0xffffffe51d249484] f2fs_is_cp_guaranteed+0x70/0x98 lr : [0xffffffe51d24adbc] f2fs_merge_page_bio+0x520/0x6d4 CPU: 3 UID: 0 PID: 6790 Comm: kworker/u16:3 Tainted: P B W OE 6.12.30-android16-5-maybe-dirty-4k #1 5f7701c9cbf727d1eebe77c89bbbeb3371e895e5 Tainted: [P]=PROPRIETARY_MODULE, [B]=BAD_PAGE, [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Workqueue: writeback wb_workfn (flush-254:49) Call trace: f2fs_is_cp_guaranteed+0x70/0x98 f2fs_inplace_write_data+0x174/0x2f4 f2fs_do_write_data_page+0x214/0x81c f2fs_write_single_data_page+0x28c/0x764 f2fs_write_data_pages+0x78c/0xce4 do_writepages+0xe8/0x2fc __writeback_single_inode+0x4c/0x4b4 writeback_sb_inodes+0x314/0x540 __writeback_inodes_wb+0xa4/0xf4 wb_writeback+0x160/0x448 wb_workfn+0x2f0/0x5dc process_scheduled_works+0x1c8/0x458 worker_thread+0x334/0x3f0 kthread+0x118/0x1ac ret_from_fork+0x10/0x20 [1] https://bugzilla.kernel.org/show_bug.cgi?id=220575 The panic was caused by UAF issue w/ below race condition: kworker - writepages - f2fs_write_cache_pages - f2fs_write_single_data_page - f2fs_do_write_data_page - f2fs_inplace_write_data - f2fs_merge_page_bio - add_inu_page : cache page #1 into bio & cache bio in io->bio_list - f2fs_write_single_data_page - f2fs_do_write_data_page - f2fs_inplace_write_data - f2fs_merge_page_bio - add_inu_page : cache page #2 into bio which is linked in io->bio_list write - f2fs_write_begin : write page #1 - f2fs_folio_wait_writeback - f2fs_submit_merged_ipu_write - f2fs_submit_write_bio : submit bio which inclues page #1 and #2 software IRQ - f2fs_write_end_io - fscrypt_free_bounce_page : freed bounced page which belongs to page #2 - inc_page_count( , WB_DATA_TYPE(data_folio), false) : data_folio points to fio->encrypted_page the bounced page can be freed before accessing it in f2fs_is_cp_guarantee() It can reproduce w/ below testcase: Run below script in shell #1: for ((i=1;i>0;i++)) do xfs_io -f /mnt/f2fs/enc/file \ -c "pwrite 0 32k" -c "fdatasync" Run below script in shell #2: for ((i=1;i>0;i++)) do xfs_io -f /mnt/f2fs/enc/file \ -c "pwrite 0 32k" -c "fdatasync" So, in f2fs_merge_page_bio(), let's avoid using fio->encrypted_page after commit page into internal ipu cache.
View original CVE JSON
{
"id": "CVE-2025-40054",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2025-10-28T12:15:39.640",
"lastModified": "2026-10-19T21:10:00.160",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix UAF issue in f2fs_merge_page_bio()\n\nAs JY reported in bugzilla [1],\n\nUnable to handle kernel NULL pointer dereference at virtual address 0000000000000000\npc : [0xffffffe51d249484] f2fs_is_cp_guaranteed+0x70/0x98\nlr : [0xffffffe51d24adbc] f2fs_merge_page_bio+0x520/0x6d4\nCPU: 3 UID: 0 PID: 6790 Comm: kworker/u16:3 Tainted: P B W OE 6.12.30-android16-5-maybe-dirty-4k #1 5f7701c9cbf727d1eebe77c89bbbeb3371e895e5\nTainted: [P]=PROPRIETARY_MODULE, [B]=BAD_PAGE, [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE\nWorkqueue: writeback wb_workfn (flush-254:49)\nCall trace:\n f2fs_is_cp_guaranteed+0x70/0x98\n f2fs_inplace_write_data+0x174/0x2f4\n f2fs_do_write_data_page+0x214/0x81c\n f2fs_write_single_data_page+0x28c/0x764\n f2fs_write_data_pages+0x78c/0xce4\n do_writepages+0xe8/0x2fc\n __writeback_single_inode+0x4c/0x4b4\n writeback_sb_inodes+0x314/0x540\n __writeback_inodes_wb+0xa4/0xf4\n wb_writeback+0x160/0x448\n wb_workfn+0x2f0/0x5dc\n process_scheduled_works+0x1c8/0x458\n worker_thread+0x334/0x3f0\n kthread+0x118/0x1ac\n ret_from_fork+0x10/0x20\n\n[1] https://bugzilla.kernel.org/show_bug.cgi?id=220575\n\nThe panic was caused by UAF issue w/ below race condition:\n\nkworker\n- writepages\n - f2fs_write_cache_pages\n - f2fs_write_single_data_page\n - f2fs_do_write_data_page\n - f2fs_inplace_write_data\n - f2fs_merge_page_bio\n - add_inu_page\n : cache page #1 into bio & cache bio in\n io->bio_list\n - f2fs_write_single_data_page\n - f2fs_do_write_data_page\n - f2fs_inplace_write_data\n - f2fs_merge_page_bio\n - add_inu_page\n : cache page #2 into bio which is linked\n in io->bio_list\n\t\t\t\t\t\twrite\n\t\t\t\t\t\t- f2fs_write_begin\n\t\t\t\t\t\t: write page #1\n\t\t\t\t\t\t - f2fs_folio_wait_writeback\n\t\t\t\t\t\t - f2fs_submit_merged_ipu_write\n\t\t\t\t\t\t - f2fs_submit_write_bio\n\t\t\t\t\t\t : submit bio which inclues page #1 and #2\n\n\t\t\t\t\t\tsoftware IRQ\n\t\t\t\t\t\t- f2fs_write_end_io\n\t\t\t\t\t\t - fscrypt_free_bounce_page\n\t\t\t\t\t\t : freed bounced page which belongs to page #2\n - inc_page_count( , WB_DATA_TYPE(data_folio), false)\n : data_folio points to fio->encrypted_page\n the bounced page can be freed before\n accessing it in f2fs_is_cp_guarantee()\n\nIt can reproduce w/ below testcase:\nRun below script in shell #1:\nfor ((i=1;i>0;i++)) do xfs_io -f /mnt/f2fs/enc/file \\\n-c \"pwrite 0 32k\" -c \"fdatasync\"\n\nRun below script in shell #2:\nfor ((i=1;i>0;i++)) do xfs_io -f /mnt/f2fs/enc/file \\\n-c \"pwrite 0 32k\" -c \"fdatasync\"\n\nSo, in f2fs_merge_page_bio(), let's avoid using fio->encrypted_page after\ncommit page into internal ipu cache."
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nf2fs: corrige el problema UAF en f2fs_merge_page_bio()\n\nComo JY informó en bugzilla [1],\n\nNo se puede manejar la desreferencia de puntero NULL del kernel en la dirección virtual 0000000000000000\npc : [0xffffffe51d249484] f2fs_is_cp_guaranteed+0x70/0x98\nlr : [0xffffffe51d24adbc] f2fs_merge_page_bio+0x520/0x6d4\nCPU: 3 UID: 0 PID: 6790 Comm: kworker/u16:3 Tainted: P B W OE 6.12.30-android16-5-maybe-dirty-4k #1 5f7701c9cbf727d1eebe77c89bbbeb3371e895e5\nTainted: [P]=MÓDULO_PROPIETARIO, [B]=PÁGINA_DAÑADA, [W]=ADVERTENCIA, [O]=MÓDULO_FUERA_DE_ÁRBOL, [E]=MÓDULO_NO_FIRMADO\nWorkqueue: writeback wb_workfn (flush-254:49)\nTraza de llamada:\n f2fs_is_cp_guaranteed+0x70/0x98\n f2fs_inplace_write_data+0x174/0x2f4\n f2fs_do_write_data_page+0x214/0x81c\n f2fs_write_single_data_page+0x28c/0x764\n f2fs_write_data_pages+0x78c/0xce4\n do_writepages+0xe8/0x2fc\n __writeback_single_inode+0x4c/0x4b4\n writeback_sb_inodes+0x314/0x540\n __writeback_inodes_wb+0xa4/0xf4\n wb_writeback+0x160/0x448\n wb_workfn+0x2f0/0x5dc\n process_scheduled_works+0x1c8/0x458\n worker_thread+0x334/0x3f0\n kthread+0x118/0x1ac\n ret_from_fork+0x10/0x20\n\n[1] https://bugzilla.kernel.org/show_bug.cgi?id=220575\n\nEl pánico fue causado por un problema UAF con la siguiente condición de carrera:\n\nkworker\n- writepages\n - f2fs_write_cache_pages\n - f2fs_write_single_data_page\n - f2fs_do_write_data_page\n - f2fs_inplace_write_data\n - f2fs_merge_page_bio\n - add_inu_page\n : almacena en caché la página #1 en bio y almacena en caché bio en\n io->bio_list\n - f2fs_write_single_data_page\n - f2fs_do_write_data_page\n - f2fs_inplace_write_data\n - f2fs_merge_page_bio\n - add_inu_page\n : almacena en caché la página #2 en bio que está vinculada\n en io->bio_list\n\t\t\t\t\t\twrite\n\t\t\t\t\t\t- f2fs_write_begin\n\t\t\t\t\t\t: escribe la página #1\n\t\t\t\t\t\t - f2fs_folio_wait_writeback\n\t\t\t\t\t\t - f2fs_submit_merged_ipu_write\n\t\t\t\t\t\t - f2fs_submit_write_bio\n\t\t\t\t\t\t : envía bio que incluye la página #1 y #2\n\n\t\t\t\t\t\tsoftware IRQ\n\t\t\t\t\t\t- f2fs_write_end_io\n\t\t\t\t\t\t - fscrypt_free_bounce_page\n\t\t\t\t\t\t : página rebotada liberada que pertenece a la página #2\n - inc_page_count( , WB_DATA_TYPE(data_folio), false)\n : data_folio apunta a fio->encrypted_page\n la página rebotada puede ser liberada antes de\n acceder a ella en f2fs_is_cp_guarantee()\n\nSe puede reproducir con el siguiente caso de prueba:\nEjecuta el siguiente script en el shell #1:\nfor ((i=1;i>0;i++)) do xfs_io -f /mnt/f2fs/enc/file \\\n-c 'pwrite 0 32k' -c 'fdatasync'\n\nEjecuta el siguiente script en el shell #2:\nfor ((i=1;i>0;i++)) do xfs_io -f /mnt/f2fs/enc/file \\\n-c 'pwrite 0 32k' -c 'fdatasync'\n\nAsí que, en f2fs_merge_page_bio(), evitemos usar fio->encrypted_page después de\nconfirmar la página en la caché ipu interna."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"fs/f2fs/data.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "0b20fcec8651569935a10afe03fedc0b812d044e",
"lessThan": "1f7b44b4a2b2939f08b279cbb9e6b5dcb8ffea32",
"versionType": "git",
"status": "affected"
},
{
"version": "0b20fcec8651569935a10afe03fedc0b812d044e",
"lessThan": "e193d8953647c8b575830852aa5ea0995b98d2b1",
"versionType": "git",
"status": "affected"
},
{
"version": "0b20fcec8651569935a10afe03fedc0b812d044e",
"lessThan": "410337c2301ae78a081e1b5ebbe8ec374fef4cb6",
"versionType": "git",
"status": "affected"
},
{
"version": "0b20fcec8651569935a10afe03fedc0b812d044e",
"lessThan": "68e094232dfe5027c4fd2dcded93d2d6800bae04",
"versionType": "git",
"status": "affected"
},
{
"version": "0b20fcec8651569935a10afe03fedc0b812d044e",
"lessThan": "7dd611131d82d7fc4212b555eb1103160bdad302",
"versionType": "git",
"status": "affected"
},
{
"version": "0b20fcec8651569935a10afe03fedc0b812d044e",
"lessThan": "01118321e0c8a5f3ece57d0d377bfc92d83cd210",
"versionType": "git",
"status": "affected"
},
{
"version": "0b20fcec8651569935a10afe03fedc0b812d044e",
"lessThan": "edf7e9040fc52c922db947f9c6c36f07377c52ea",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"fs/f2fs/data.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "5.5",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.5",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.266",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.217",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.184",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.153",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.105",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.17.3",
"lessThanOrEqual": "6.17.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/01118321e0c8a5f3ece57d0d377bfc92d83cd210",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/1f7b44b4a2b2939f08b279cbb9e6b5dcb8ffea32",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/410337c2301ae78a081e1b5ebbe8ec374fef4cb6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/68e094232dfe5027c4fd2dcded93d2d6800bae04",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/7dd611131d82d7fc4212b555eb1103160bdad302",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e193d8953647c8b575830852aa5ea0995b98d2b1",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/edf7e9040fc52c922db947f9c6c36f07377c52ea",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}