In the Linux kernel, the following vulnerability has been resolved:
ext4: don't allow journal inode to have encrypt flag
Mounting a filesystem whose journal inode has the encrypt flag causes a
NULL dereference in fscrypt_limit_io_blocks() when the 'inlinecrypt'
mount option is used.
The problem is that when jbd2_journal_init_inode() calls bmap(), it
eventually finds its way into ext4_iomap_begin(), which calls
fscrypt_limit_io_blocks(). fscrypt_limit_io_blocks() requires that if
the inode is encrypted, then its encryption key must already be set up.
That's not the case here, since the journal inode is never "opened" like
a normal file would be. Hence the crash.
A reproducer is:
mkfs.ext4 -F /dev/vdb
debugfs -w /dev/vdb -R "set_inode_field <8> flags 0x80808"
mount /dev/vdb /mnt -o inlinecrypt
To fix this, make ext4 consider journal inodes with the encrypt flag to
be invalid. (Note, maybe other flags should be rejected on the journal
inode too. For now, this is just the minimal fix for the above issue.)
I've marked this as fixing the commit that introduced the call to
fscrypt_limit_io_blocks(), since that's what made an actual crash start
being possible. But this fix could be applied to any version of ext4
that supports the encrypt feature.
References
Configurations
Configuration 1 (hide)
|
History
03 Dec 2025, 18:31
| Type | Values Removed | Values Added |
|---|---|---|
| CWE | CWE-476 | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| References | () https://git.kernel.org/stable/c/105c78e12468413e426625831faa7db4284e1fec - Patch | |
| References | () https://git.kernel.org/stable/c/1f7a6626f611aa06d7907aa45b484708dd5ac8bc - Patch | |
| References | () https://git.kernel.org/stable/c/bcc5057e1781a3ee889225480d995c3b5cbde555 - Patch | |
| First Time |
Linux
Linux linux Kernel |
|
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
Information
Published : 2025-09-15 15:15
Updated : 2025-12-03 18:31
NVD link : CVE-2022-50277
Mitre link : CVE-2022-50277
CVE.ORG link : CVE-2022-50277
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-476
NULL Pointer Dereference
