cbcvebase.
CVE-2025-39775
published 2025-09-11

CVE-2025-39775: In the Linux kernel, the following vulnerability has been resolved: mm/mremap: fix WARN with uffd that has remap events disabled Registering userfaultd on a…

PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.12%
2.1th percentile
In the Linux kernel, the following vulnerability has been resolved: mm/mremap: fix WARN with uffd that has remap events disabled Registering userfaultd on a VMA that spans at least one PMD and then mremap()'ing that VMA can trigger a WARN when recovering from a failed page table move due to a page table allocation error. The code ends up doing the right thing (recurse, avoiding moving actual page tables), but triggering that WARN is unpleasant: WARNING: CPU: 2 PID: 6133 at mm/mremap.c:357 move_normal_pmd mm/mremap.c:357 [inline] WARNING: CPU: 2 PID: 6133 at mm/mremap.c:357 move_pgt_entry mm/mremap.c:595 [inline] WARNING: CPU: 2 PID: 6133 at mm/mremap.c:357 move_page_tables+0x3832/0x44a0 mm/mremap.c:852 Modules linked in: CPU: 2 UID: 0 PID: 6133 Comm: syz.0.19 Not tainted 6.17.0-rc1-syzkaller-00004-g53e760d89498 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:move_normal_pmd mm/mremap.c:357 [inline] RIP: 0010:move_pgt_entry mm/mremap.c:595 [inline] RIP: 0010:move_page_tables+0x3832/0x44a0 mm/mremap.c:852 Code: ... RSP: 0018:ffffc900037a76d8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000032930007 RCX: ffffffff820c6645 RDX: ffff88802e56a440 RSI: ffffffff820c7201 RDI: 0000000000000007 RBP: ffff888037728fc0 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000032930007 R11: 0000000000000000 R12: 0000000000000000 R13: ffffc900037a79a8 R14: 0000000000000001 R15: dffffc0000000000 FS: 000055556316a500(0000) GS:ffff8880d68bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30863fff CR3: 0000000050171000 CR4: 0000000000352ef0 Call Trace: copy_vma_and_data+0x468/0x790 mm/mremap.c:1215 move_vma+0x548/0x1780 mm/mremap.c:1282 mremap_to+0x1b7/0x450 mm/mremap.c:1406 do_mremap+0xfad/0x1f80 mm/mremap.c:1921 __do_sys_mremap+0x119/0x170 mm/mremap.c:1977 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscal

Affected

11 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.16.5-1 (forky)linux 6.16.5-1 (forky)
linuxlinux
linuxlinux
linuxlinux>= 0cef0bb836e3cfe00f08f9606c72abd72fe78ca3 < d70ca21f7bff162a5afae1ddd6f4107adf05ae23d70ca21f7bff162a5afae1ddd6f4107adf05ae23
linuxlinux>= 0cef0bb836e3cfe00f08f9606c72abd72fe78ca3 < 772e5b4a5e8360743645b9a466842d16092c4f94772e5b4a5e8360743645b9a466842d16092c4f94
linuxlinux>= 6.12.11 < 6.136.13
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.16.5-16.16.5-1
linuxlinux_kernel>= 6.12.11 < 6.136.13
linuxlinux_kernel>= 6.13.1 < 6.16.46.16.4

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5LOW
vendor_redhat5.5MEDIUM
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