UBUNTU-CVE-2024-49883
In the Linux kernel, the following vulnerability has been resolved: ext4: aovid use-after-free in ext4_ext_insert_extent() As Ojaswin mentioned in Link, in ext4_ext_insert_extent(), if the path is reallocated in ext4_ext_create_new_leaf(), we'll use the stale path and cause UAF. Below is a sample trace with dummy values: ext4_ext_insert_extent path = *ppath = 2000 ext4_ext_create_new_leaf(ppath) ext4_find_extent(ppath) path = *ppath = 2000 if (depth > path[0].p_maxdepth) kfree(path = 2000); *ppath = path = NULL; path = kcalloc() = 3000 *ppath = 3000; return path; /* here path is still 2000, UAF! */ eh = path[depth].p_hdr ================================================================== BUG: KASAN: slab-use-after-free in ext4_ext_insert_extent+0x26d4/0x3330 Read of size 8 at addr ffff8881027bf7d0 by task kworker/u36:1/179 CPU: 3 UID: 0 PID: 179 Comm: kworker/u6:1 Not tainted 6.11.0-rc2-dirty #866 Call Trace: <TASK> ext4_ext_insert_extent+0x26d4/0x3330 ext4_ext_map_blocks+0xe22/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 [...] Allocated by task 179: ext4_find_extent+0x81c/0x1f70 ext4_ext_map_blocks+0x146/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 ext4_writepages+0x26d/0x4e0 do_writepages+0x175/0x700 [...] Freed by task 179: kfree+0xcb/0x240 ext4_find_extent+0x7c0/0x1f70 ext4_ext_insert_extent+0xa26/0x3330 ext4_ext_map_blocks+0xe22/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 ext4_writepages+0x26d/0x4e0 do_writepages+0x175/0x700 [...] ================================================================== So use *ppath to update the path to avoid the above problem.
02 / AFFECTED SOFTWARE
Affected packages
63 explicit affected versions
56 explicit affected versions
19 explicit affected versions
26 explicit affected versions
18 explicit affected versions
37 explicit affected versions
79 explicit affected versions
31 explicit affected versions
1 explicit affected versions
1 explicit affected versions
74 explicit affected versions
14 explicit affected versions
35 explicit affected versions
84 explicit affected versions
13 explicit affected versions
55 explicit affected versions
14 explicit affected versions
3 explicit affected versions
21 explicit affected versions
13 explicit affected versions
11 explicit affected versions
39 explicit affected versions
53 explicit affected versions
10 explicit affected versions
87 explicit affected versions
21 explicit affected versions
16 explicit affected versions
10 explicit affected versions
50 explicit affected versions
6 explicit affected versions
12 explicit affected versions
19 explicit affected versions
6 explicit affected versions
10 explicit affected versions
17 explicit affected versions
48 explicit affected versions
72 explicit affected versions
58 explicit affected versions
49 explicit affected versions
11 explicit affected versions
17 explicit affected versions
55 explicit affected versions
7 explicit affected versions
54 explicit affected versions
12 explicit affected versions
99 explicit affected versions
13 explicit affected versions
15 explicit affected versions
18 explicit affected versions
18 explicit affected versions
16 explicit affected versions
105 explicit affected versions
64 explicit affected versions
17 explicit affected versions
101 explicit affected versions
13 explicit affected versions
4 explicit affected versions
23 explicit affected versions
110 explicit affected versions
22 explicit affected versions
1 explicit affected versions
10 explicit affected versions
18 explicit affected versions
7 explicit affected versions
12 explicit affected versions
1 explicit affected versions
46 explicit affected versions
12 explicit affected versions
14 explicit affected versions
7 explicit affected versions
12 explicit affected versions
88 explicit affected versions
12 explicit affected versions
104 explicit affected versions
112 explicit affected versions
12 explicit affected versions
99 explicit affected versions
109 explicit affected versions
14 explicit affected versions
11 explicit affected versions
4 explicit affected versions
13 explicit affected versions
10 explicit affected versions
177 explicit affected versions
37 explicit affected versions
1 explicit affected versions
10 explicit affected versions
33 explicit affected versions
1 explicit affected versions
37 explicit affected versions
26 explicit affected versions
13 explicit affected versions
10 explicit affected versions
1 explicit affected versions
29 explicit affected versions
92 explicit affected versions
13 explicit affected versions
60 explicit affected versions
11 explicit affected versions
12 explicit affected versions
1 explicit affected versions
87 explicit affected versions
57 explicit affected versions
104 explicit affected versions
33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
1 explicit affected versions
140 explicit affected versions
103 explicit affected versions
11 explicit affected versions
12 explicit affected versions
126 explicit affected versions
7 explicit affected versions
12 explicit affected versions
102 explicit affected versions
2 explicit affected versions
46 explicit affected versions
10 explicit affected versions
40 explicit affected versions
119 explicit affected versions
56 explicit affected versions
154 explicit affected versions
1 explicit affected versions
10 explicit affected versions
20 explicit affected versions
13 explicit affected versions
27 explicit affected versions
19 explicit affected versions
126 explicit affected versions
62 explicit affected versions
16 explicit affected versions
59 explicit affected versions
20 explicit affected versions
47 explicit affected versions
3 explicit affected versions
80 explicit affected versions
1 explicit affected versions
1 explicit affected versions
2 explicit affected versions
69 explicit affected versions
51 explicit affected versions
7 explicit affected versions
17 explicit affected versions
12 explicit affected versions
45 explicit affected versions
8 explicit affected versions
20 explicit affected versions
5 explicit affected versions
8 explicit affected versions
1 explicit affected versions
16 explicit affected versions
13 explicit affected versions
91 explicit affected versions
13 explicit affected versions
7 explicit affected versions
2 explicit affected versions
81 explicit affected versions
50 explicit affected versions
10 explicit affected versions
12 explicit affected versions
91 explicit affected versions
44 explicit affected versions
16 explicit affected versions
13 explicit affected versions
26 explicit affected versions
45 explicit affected versions
37 explicit affected versions
11 explicit affected versions
14 explicit affected versions
38 explicit affected versions
49 explicit affected versions
9 explicit affected versions
48 explicit affected versions
11 explicit affected versions
7 explicit affected versions
56 explicit affected versions
7 explicit affected versions
29 explicit affected versions
63 explicit affected versions
130 explicit affected versions
109 explicit affected versions
4 explicit affected versions
1 explicit affected versions
1 explicit affected versions
1 explicit affected versions
54 explicit affected versions
102 explicit affected versions
43 explicit affected versions
57 explicit affected versions
133 explicit affected versions
154 explicit affected versions
10 explicit affected versions
8 explicit affected versions
15 explicit affected versions
14 explicit affected versions
92 explicit affected versions
4 explicit affected versions
78 explicit affected versions
11 explicit affected versions
1 explicit affected versions
56 explicit affected versions
12 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: ext4: aovid use-after-free in ext4_ext_insert_extent() As Ojaswin mentioned in Link, in ext4_ext_insert_extent(), if the path is reallocated in ext4_ext_create_new_leaf(), we'll use the stale path and cause UAF. Below is a sample trace with dummy values: ext4_ext_insert_extent path = *ppath = 2000 ext4_ext_create_new_leaf(ppath) ext4_find_extent(ppath) path = *ppath = 2000 if (depth > path[0].p_maxdepth) kfree(path = 2000); *ppath = path = NULL; path = kcalloc() = 3000 *ppath = 3000; return path; /* here path is still 2000, UAF! */ eh = path[depth].p_hdr ================================================================== BUG: KASAN: slab-use-after-free in ext4_ext_insert_extent+0x26d4/0x3330 Read of size 8 at addr ffff8881027bf7d0 by task kworker/u36:1/179 CPU: 3 UID: 0 PID: 179 Comm: kworker/u6:1 Not tainted 6.11.0-rc2-dirty #866 Call Trace: <TASK> ext4_ext_insert_extent+0x26d4/0x3330 ext4_ext_map_blocks+0xe22/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 [...] Allocated by task 179: ext4_find_extent+0x81c/0x1f70 ext4_ext_map_blocks+0x146/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 ext4_writepages+0x26d/0x4e0 do_writepages+0x175/0x700 [...] Freed by task 179: kfree+0xcb/0x240 ext4_find_extent+0x7c0/0x1f70 ext4_ext_insert_extent+0xa26/0x3330 ext4_ext_map_blocks+0xe22/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 ext4_writepages+0x26d/0x4e0 do_writepages+0x175/0x700 [...] ================================================================== So use *ppath to update the path to avoid the above problem.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/a164f3a432aae62ca23d03e6d926b122ee5b860d
- https://git.kernel.org/stable/c/51db04892a993cace63415be99848970a0f15ef2
- https://git.kernel.org/stable/c/5e811066c5ab709b070659197dccfb80ab650ddd
- https://git.kernel.org/stable/c/8162ee5d94b8c0351be0a9321be134872a7654a1
- https://git.kernel.org/stable/c/9df59009dfc6d9fc1bd9ddf6c5ab6e56d6ed887a
- https://git.kernel.org/stable/c/a164f3a432aae62ca23d03e6d926b122ee5b860d
- https://git.kernel.org/stable/c/beb7b66fb489041c50c6473100b383f7a51648fc
- https://git.kernel.org/stable/c/bfed082ce4b1ce6349b05c09a0fa4f3da35ecb1b
- https://ubuntu.com/security/CVE-2024-49883
- https://ubuntu.com/security/notices/USN-7166-1
- https://ubuntu.com/security/notices/USN-7166-2
- https://ubuntu.com/security/notices/USN-7166-3
- https://ubuntu.com/security/notices/USN-7166-4
- https://ubuntu.com/security/notices/USN-7186-1
- https://ubuntu.com/security/notices/USN-7186-2
- https://ubuntu.com/security/notices/USN-7194-1
- https://ubuntu.com/security/notices/USN-7276-1
- https://ubuntu.com/security/notices/USN-7277-1
- https://ubuntu.com/security/notices/USN-7293-1
- https://ubuntu.com/security/notices/USN-7294-1
- https://ubuntu.com/security/notices/USN-7294-2
- https://ubuntu.com/security/notices/USN-7294-3
- https://ubuntu.com/security/notices/USN-7294-4
- https://ubuntu.com/security/notices/USN-7295-1
- https://ubuntu.com/security/notices/USN-7301-1
- https://ubuntu.com/security/notices/USN-7303-1
- https://ubuntu.com/security/notices/USN-7303-2
- https://ubuntu.com/security/notices/USN-7303-3
- https://ubuntu.com/security/notices/USN-7304-1
- https://ubuntu.com/security/notices/USN-7310-1
- https://ubuntu.com/security/notices/USN-7311-1
- https://ubuntu.com/security/notices/USN-7384-1
- https://ubuntu.com/security/notices/USN-7384-2
- https://ubuntu.com/security/notices/USN-7385-1
- https://ubuntu.com/security/notices/USN-7386-1
- https://ubuntu.com/security/notices/USN-7393-1
- https://ubuntu.com/security/notices/USN-7401-1
- https://ubuntu.com/security/notices/USN-7403-1
- https://ubuntu.com/security/notices/USN-7413-1
- https://ubuntu.com/security/notices/USN-7468-1
- https://ubuntu.com/security/notices/USN-7539-1
- https://ubuntu.com/security/notices/USN-7540-1
- https://ubuntu.com/security/notices/USN-7684-1
- https://ubuntu.com/security/notices/USN-7684-2
- https://ubuntu.com/security/notices/USN-7684-3
- https://ubuntu.com/security/notices/USN-7685-1
- https://ubuntu.com/security/notices/USN-7685-2
- https://ubuntu.com/security/notices/USN-7685-3
- https://ubuntu.com/security/notices/USN-7685-4
- https://ubuntu.com/security/notices/USN-7685-5
- https://www.cve.org/CVERecord?id=CVE-2024-49883