{"id":"DEBIAN-CVE-2025-39866","details":"In the Linux kernel, the following vulnerability has been resolved:  fs: writeback: fix use-after-free in __mark_inode_dirty()  An use-after-free issue occurred when __mark_inode_dirty() get the bdi_writeback that was in the progress of switching.  CPU: 1 PID: 562 Comm: systemd-random- Not tainted 6.6.56-gb4403bd46a8e #1 ...... pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __mark_inode_dirty+0x124/0x418 lr : __mark_inode_dirty+0x118/0x418 sp : ffffffc08c9dbbc0 ........ Call trace:  __mark_inode_dirty+0x124/0x418  generic_update_time+0x4c/0x60  file_modified+0xcc/0xd0  ext4_buffered_write_iter+0x58/0x124  ext4_file_write_iter+0x54/0x704  vfs_write+0x1c0/0x308  ksys_write+0x74/0x10c  __arm64_sys_write+0x1c/0x28  invoke_syscall+0x48/0x114  el0_svc_common.constprop.0+0xc0/0xe0  do_el0_svc+0x1c/0x28  el0_svc+0x40/0xe4  el0t_64_sync_handler+0x120/0x12c  el0t_64_sync+0x194/0x198  Root cause is:  systemd-random-seed                         kworker ---------------------------------------------------------------------- ___mark_inode_dirty                     inode_switch_wbs_work_fn    spin_lock(&inode-\u003ei_lock);   inode_attach_wb   locked_inode_to_wb_and_lock_list      get inode-\u003ei_wb      spin_unlock(&inode-\u003ei_lock);      spin_lock(&wb-\u003elist_lock)   spin_lock(&inode-\u003ei_lock)   inode_io_list_move_locked   spin_unlock(&wb-\u003elist_lock)   spin_unlock(&inode-\u003ei_lock)                                     spin_lock(&old_wb-\u003elist_lock)                                       inode_do_switch_wbs                                         spin_lock(&inode-\u003ei_lock)                                         inode-\u003ei_wb = new_wb                                         spin_unlock(&inode-\u003ei_lock)                                     spin_unlock(&old_wb-\u003elist_lock)                                     wb_put_many(old_wb, nr_switched)                                       cgwb_release                                       old wb released   wb_wakeup_delayed() accesses wb,   then trigger the use-after-free   issue  Fix this race condition by holding inode spinlock until wb_wakeup_delayed() finished.","modified":"2026-09-01T16:06:16.198811480Z","published":"2025-09-19T16:15:45.657Z","upstream":["CVE-2025-39866"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2025-39866"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.153-1"}]}],"versions":["6.1.106-1","6.1.106-2","6.1.106-3","6.1.112-1","6.1.115-1","6.1.119-1","6.1.123-1","6.1.124-1","6.1.128-1","6.1.129-1","6.1.133-1","6.1.135-1","6.1.137-1","6.1.139-1","6.1.140-1","6.1.147-1","6.1.148-1","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","6.1.52-1","6.1.55-1","6.1.55-1~bpo11+1","6.1.64-1","6.1.66-1","6.1.67-1","6.1.69-1","6.1.69-1~bpo11+1","6.1.76-1","6.1.76-1~bpo11+1","6.1.82-1","6.1.85-1","6.1.90-1","6.1.90-1~bpo11+1","6.1.94-1","6.1.94-1~bpo11+1","6.1.98-1","6.1.99-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-39866.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.12.48-1"}]}],"versions":["6.12.38-1","6.12.41-1","6.12.43-1","6.12.43-1~bpo12+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-39866.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.16.6-1"}]}],"versions":["6.12.100-1","6.12.101-1","6.12.105-1","6.12.107-1","6.12.38-1","6.12.41-1","6.12.43-1","6.12.43-1~bpo12+1","6.12.48-1","6.12.57-1","6.12.57-1~bpo12+1","6.12.63-1","6.12.63-1~bpo12+1","6.12.69-1","6.12.69-1~bpo12+1","6.12.73-1","6.12.73-1~bpo12+1","6.12.74-1","6.12.74-2","6.12.74-2~bpo12+1","6.12.85-1","6.12.85-1~bpo12+1","6.12.86-1","6.12.86-1~bpo12+1","6.12.88-1","6.12.88-1~bpo12+1","6.12.90-1","6.12.90-1~bpo12+1","6.12.90-2","6.12.90-2~bpo12+1","6.12.94-1","6.12.94-1~bpo12+1","6.12.95-1","6.12.95-1~bpo12+1","6.12.96-1","6.13.10-1~exp1","6.13.11-1~exp1","6.13.2-1~exp1","6.13.3-1~exp1","6.13.4-1~exp1","6.13.5-1~exp1","6.13.6-1~exp1","6.13.7-1~exp1","6.13.8-1~exp1","6.13.9-1~exp1","6.13~rc6-1~exp1","6.13~rc7-1~exp1","6.14.3-1~exp1","6.14.5-1~exp1","6.14.6-1~exp1","6.15-1~exp1","6.15.1-1~exp1","6.15.2-1~exp1","6.15.3-1~exp1","6.15.4-1~exp1","6.15.5-1~exp1","6.15.6-1~exp1","6.15~rc7-1~exp1","6.16-1~exp1","6.16.1-1~exp1","6.16.3-1","6.16.3-1~bpo13+1","6.16.5-1","6.16~rc7-1~exp1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-39866.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:H/I:H/A:H"}]}