In the Linux kernel, the following vulnerability has been resolved:
mm/vma: fix memory leak in __mmap_region()
commit 605f6586ecf7 ("mm/vma: do not leak memory when .mmap_prepare
swaps the file") handled the success path by skipping get_file() via
file_doesnt_need_get, but missed the error path.
When /dev/zero is mmap'd with MAP_SHARED, mmap_zero_prepare() calls
shmem_zero_setup_desc() which allocates a new shmem file to back the
mapping. If __mmap_new_vma() subsequently fails, this replacement
file is never fput()'d - the original is released by
ksys_mmap_pgoff(), but nobody releases the new one.
Add fput() for the swapped file in the error path.
Reproducible with fault injection.
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 1
CPU: 2 UID: 0 PID: 366 Comm: syz.7.14 Not tainted 7.0.0-rc6 #2 PREEMPT(full)
Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x164/0x1f0
should_fail_ex+0x525/0x650
should_failslab+0xdf/0x140
kmem_cache_alloc_noprof+0x78/0x630
vm_area_alloc+0x24/0x160
__mmap_region+0xf6b/0x2660
mmap_region+0x2eb/0x3a0
do_mmap+0xc79/0x1240
vm_mmap_pgoff+0x252/0x4c0
ksys_mmap_pgoff+0xf8/0x120
__x64_sys_mmap+0x12a/0x190
do_syscall_64+0xa9/0x580
entry_SYSCALL_64_after_hwframe+0x76/0x7e
</TASK>
kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
BUG: memory leak
unreferenced object 0xffff8881118aca80 (size 360):
comm "syz.7.14", pid 366, jiffies 4294913255
hex dump (first 32 bytes):
00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
ff ff ff ff ff ff ff ff c0 28 4d ae ff ff ff ff .........(M.....
backtrace (crc db0f53bc):
kmem_cache_alloc_noprof+0x3ab/0x630
alloc_empty_file+0x5a/0x1e0
alloc_file_pseudo+0x135/0x220
__shmem_file_setup+0x274/0x420
shmem_zero_setup_desc+0x9c/0x170
mmap_zero_prepare+0x123/0x140
__mmap_region+0xdda/0x2660
mmap_region+0x2eb/0x3a0
do_mmap+0xc79/0x1240
vm_mmap_pgoff+0x252/0x4c0
ksys_mmap_pgoff+0xf8/0x120
__x64_sys_mmap+0x12a/0x190
do_syscall_64+0xa9/0x580
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Found by syzkaller.
References
Configurations
Configuration 1 (hide)
|
History
27 Apr 2026, 20:16
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.19:-:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:* |
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| First Time |
Linux
Linux linux Kernel |
|
| CWE | CWE-401 | |
| References | () https://git.kernel.org/stable/c/61fc8eaf2ab214b32c7bce52597c80cf0ca41ada - Patch | |
| References | () https://git.kernel.org/stable/c/894f99eb535edc4514f756818f3c4f688ba53a59 - Patch |
24 Apr 2026, 15:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-04-24 15:16
Updated : 2026-04-27 20:16
NVD link : CVE-2026-31654
Mitre link : CVE-2026-31654
CVE.ORG link : CVE-2026-31654
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-401
Missing Release of Memory after Effective Lifetime