Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: fs/proc: fix uaf in proc_readdir_de() Pde is erased from subdir rbtree through rb_erase(), but not set the node to EMPTY, which may result in uaf access. We should use RB_CLEAR_NODE() set the erased node to EMPTY, then pde_subdir_next() will return NULL to avoid uaf access. We found an uaf issue while using stress-ng testing, need to run testcase getdent and tun in the same time. The steps of the issue is as follows: 1) use getdent to traverse dir /proc/pid/net/dev_snmp6/, and current pde is tun3; 2) in the [time windows] unregister netdevice tun3 and tun2, and erase them from rbtree. erase tun3 first, and then erase tun2. the pde(tun2) will be released to slab; 3) continue to getdent process, then pde_subdir_next() will return pde(tun2) which is released, it will case uaf access. CPU 0 | CPU 1 ------------------------------------------------------------------------- traverse dir /proc/pid/net/dev_snmp6/ | unregister_netdevice(tun->dev) //tun3 tun2 sys_getdents64() | iterate_dir() | proc_readdir() | proc_readdir_de() | snmp6_unregister_dev() pde_get(de); | proc_remove() read_unlock(&proc_subdir_lock); | remove_proc_subtree() | write_lock(&proc_subdir_lock); [time window] | rb_erase(&root->subdir_node, &parent->subdir); | write_unlock(&proc_subdir_lock); read_lock(&proc_subdir_lock); | next = pde_subdir_next(de); | pde_put(de); | de = next; //UAF | rbtree of dev_snmp6 | pde(tun3) / \ NULL pde(tun2)
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 710585d4922fd315f2cada8fbe550ae8ed23e994 before 1d1596d68a6f11d28f677eedf6cf5b17dbfeb491; affected 710585d4922fd315f2cada8fbe550ae8ed23e994 before c81d0385500446efe48c305bbb83d47f2ae23a50; affected 710585d4922fd315f2cada8fbe550ae8ed23e994 before 4cba73c4c89219beef7685a47374bf88b1022369; affected 710585d4922fd315f2cada8fbe550ae8ed23e994 before 6f2482745e510ae1dacc9b090194b9c5f918d774; affected 710585d4922fd315f2cada8fbe550ae8ed23e994 before 67272c11f379d9aa5e0f6b16286b9d89b3f76046; affected 710585d4922fd315f2cada8fbe550ae8ed23e994 before 623bb26127fb581a741e880e1e1a47d79aecb6f8; affected 710585d4922fd315f2cada8fbe550ae8ed23e994 before 03de7ff197a3d0e17d0d5c58fdac99a63cba8110; affected 710585d4922fd315f2cada8fbe550ae8ed23e994 before 895b4c0c79b092d732544011c3cecaf7322c36a1 |
| Linux / Linux | affected 3.19; unaffected 0 before 3.19; unaffected 5.4.302 through 5.4.*; unaffected 5.10.247 through 5.10.*; unaffected 5.15.197 through 5.15.*; unaffected 6.1.159 through 6.1.*; unaffected 6.6.117 through 6.6.*; unaffected 6.12.59 through 6.12.*; unaffected 6.17.9 through 6.17.*; unaffected 6.18 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/1d1596d68a6f11d28f677eedf6cf5b17dbfeb491
- https://git.kernel.org/stable/c/c81d0385500446efe48c305bbb83d47f2ae23a50
- https://git.kernel.org/stable/c/4cba73c4c89219beef7685a47374bf88b1022369
- https://git.kernel.org/stable/c/6f2482745e510ae1dacc9b090194b9c5f918d774
- https://git.kernel.org/stable/c/67272c11f379d9aa5e0f6b16286b9d89b3f76046
- https://git.kernel.org/stable/c/623bb26127fb581a741e880e1e1a47d79aecb6f8
- https://git.kernel.org/stable/c/03de7ff197a3d0e17d0d5c58fdac99a63cba8110
- https://git.kernel.org/stable/c/895b4c0c79b092d732544011c3cecaf7322c36a1
ADP enrichment
No English description supplied.
No English description supplied.
No references supplied.