CVE-2022-50673
ext4: fix use-after-free in ext4_orphan_cleanup
Description
In the Linux kernel, the following vulnerability has been resolved: ext4: fix use-after-free in ext4_orphan_cleanup I caught a issue as follows: ================================================================== BUG: KASAN: use-after-free in __list_add_valid+0x28/0x1a0 Read of size 8 at addr ffff88814b13f378 by task mount/710 CPU: 1 PID: 710 Comm: mount Not tainted 6.1.0-rc3-next #370 Call Trace: <TASK> dump_stack_lvl+0x73/0x9f print_report+0x25d/0x759 kasan_report+0xc0/0x120 __asan_load8+0x99/0x140 __list_add_valid+0x28/0x1a0 ext4_orphan_cleanup+0x564/0x9d0 [ext4] __ext4_fill_super+0x48e2/0x5300 [ext4] ext4_fill_super+0x19f/0x3a0 [ext4] get_tree_bdev+0x27b/0x450 ext4_get_tree+0x19/0x30 [ext4] vfs_get_tree+0x49/0x150 path_mount+0xaae/0x1350 do_mount+0xe2/0x110 __x64_sys_mount+0xf0/0x190 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK> [...] ================================================================== Above issue may happen as follows: ------------------------------------- ext4_fill_super ext4_orphan_cleanup --- loop1: assume last_orphan is 12 --- list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan) ext4_truncate --> return 0 ext4_inode_attach_jinode --> return -ENOMEM iput(inode) --> free inode<12> --- loop2: last_orphan is still 12 --- list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan); // use inode<12> and trigger UAF To solve this issue, we need to propagate the return value of ext4_inode_attach_jinode() appropriately.
INFO
Published Date :
Dec. 9, 2025, 4:17 p.m.
Last Modified :
Dec. 9, 2025, 6:37 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Apply the provided kernel patch.
- Update to a fixed Linux kernel version.
- Propagate the return value of ext4_inode_attach_jinode.
References to Advisories, Solutions, and Tools
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CVE-2022-50673.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2022-50673 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
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stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2022-50673
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Dec. 09, 2025
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: ext4: fix use-after-free in ext4_orphan_cleanup I caught a issue as follows: ================================================================== BUG: KASAN: use-after-free in __list_add_valid+0x28/0x1a0 Read of size 8 at addr ffff88814b13f378 by task mount/710 CPU: 1 PID: 710 Comm: mount Not tainted 6.1.0-rc3-next #370 Call Trace: <TASK> dump_stack_lvl+0x73/0x9f print_report+0x25d/0x759 kasan_report+0xc0/0x120 __asan_load8+0x99/0x140 __list_add_valid+0x28/0x1a0 ext4_orphan_cleanup+0x564/0x9d0 [ext4] __ext4_fill_super+0x48e2/0x5300 [ext4] ext4_fill_super+0x19f/0x3a0 [ext4] get_tree_bdev+0x27b/0x450 ext4_get_tree+0x19/0x30 [ext4] vfs_get_tree+0x49/0x150 path_mount+0xaae/0x1350 do_mount+0xe2/0x110 __x64_sys_mount+0xf0/0x190 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK> [...] ================================================================== Above issue may happen as follows: ------------------------------------- ext4_fill_super ext4_orphan_cleanup --- loop1: assume last_orphan is 12 --- list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan) ext4_truncate --> return 0 ext4_inode_attach_jinode --> return -ENOMEM iput(inode) --> free inode<12> --- loop2: last_orphan is still 12 --- list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan); // use inode<12> and trigger UAF To solve this issue, we need to propagate the return value of ext4_inode_attach_jinode() appropriately. Added Reference https://git.kernel.org/stable/c/026a4490b5381229a30f23d073b58e8e35ee6858 Added Reference https://git.kernel.org/stable/c/7223d5e75f26352354ea2c0ccf8b579821b52adf Added Reference https://git.kernel.org/stable/c/7908b8a541b1578cc61b4da7f19b604a931441da Added Reference https://git.kernel.org/stable/c/7f801a1593cb957f73659732836b2dafbdfc7709 Added Reference https://git.kernel.org/stable/c/a71248b1accb2b42e4980afef4fa4a27fa0e36f5 Added Reference https://git.kernel.org/stable/c/c2bdbd4c69308835d1b6f6ba74feeccbfe113478 Added Reference https://git.kernel.org/stable/c/cf0e0817b0f925b70d101d7014ea81b7094e1159