CVE-2021-47585
btrfs: fix memory leak in __add_inode_ref()
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix memory leak in __add_inode_ref()
Line 1169 (#3) allocates a memory chunk for victim_name by kmalloc(),
but when the function returns in line 1184 (#4) victim_name allocated
by line 1169 (#3) is not freed, which will lead to a memory leak.
There is a similar snippet of code in this function as allocating a memory
chunk for victim_name in line 1104 (#1) as well as releasing the memory
in line 1116 (#2).
We should kfree() victim_name when the return value of backref_in_log()
is less than zero and before the function returns in line 1184 (#4).
1057 static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
1058 struct btrfs_root *root,
1059 struct btrfs_path *path,
1060 struct btrfs_root *log_root,
1061 struct btrfs_inode *dir,
1062 struct btrfs_inode *inode,
1063 u64 inode_objectid, u64 parent_objectid,
1064 u64 ref_index, char *name, int namelen,
1065 int *search_done)
1066 {
1104 victim_name = kmalloc(victim_name_len, GFP_NOFS);
// #1: kmalloc (victim_name-1)
1105 if (!victim_name)
1106 return -ENOMEM;
1112 ret = backref_in_log(log_root, &search_key,
1113 parent_objectid, victim_name,
1114 victim_name_len);
1115 if (ret < 0) {
1116 kfree(victim_name); // #2: kfree (victim_name-1)
1117 return ret;
1118 } else if (!ret) {
1169 victim_name = kmalloc(victim_name_len, GFP_NOFS);
// #3: kmalloc (victim_name-2)
1170 if (!victim_name)
1171 return -ENOMEM;
1180 ret = backref_in_log(log_root, &search_key,
1181 parent_objectid, victim_name,
1182 victim_name_len);
1183 if (ret < 0) {
1184 return ret; // #4: missing kfree (victim_name-2)
1185 } else if (!ret) {
1241 return 0;
1242 }
En el kernel de Linux, se resolvió la siguiente vulnerabilidad: btrfs: corrige la pérdida de memoria en __add_inode_ref() La línea 1169 (#3) asigna un fragmento de memoria para victim_name mediante kmalloc(), pero cuando la función regresa en la línea 1184 (#4) victim_name asignado por la línea 1169 (#3) no se libera, lo que provocará una pérdida de memoria. Hay un fragmento de código similar en esta función para asignar un fragmento de memoria para victim_name en la línea 1104 (n.º 1), así como para liberar la memoria en la línea 1116 (n.º 2). Deberíamos kfree() victim_name cuando el valor de retorno de backref_in_log() sea menor que cero y antes de que la función regrese en la línea 1184 (#4). 1057 static inline int __add_inode_ref(struct btrfs_trans_handle *trans, 1058 struct btrfs_root *root, 1059 struct btrfs_path *path, 1060 struct btrfs_root *log_root, 1061 struct btrfs_inode *dir, 1062 struct btrfs_inode *inode, 63 u64 inode_objectid, u64 parent_objectid, 1064 u64 ref_index, char *nombre, int nombrelen, 1065 int *search_done) 1066 { 1104 nombre_víctima = kmalloc(nombre_víctima_len, GFP_NOFS); // #1: kmalloc (nombre_víctima-1) 1105 if (!nombre_víctima) 1106 return -ENOMEM; 1112 ret = backref_in_log(log_root, &search_key, 1113 parent_objectid, victim_name, 1114 victim_name_len); 1115 if (ret < 0) { 1116 kfree(nombre_víctima); // #2: kfree (nombre_víctima-1) 1117 return ret; 1118 } else if (!ret) { 1169 nombre_víctima = kmalloc(nombre_víctima_len, GFP_NOFS); // #3: kmalloc (nombre_víctima-2) 1170 if (!nombre_víctima) 1171 return -ENOMEM; 1180 ret = backref_in_log(log_root, &search_key, 1181 parent_objectid, victim_name, 1182 victim_name_len); 1183 si (ret < 0) { 1184 retorno ret; // #4: falta kfree (nombre_víctima-2) 1185 } else if (!ret) { 1241 return 0; 1242 }
CVSS Scores
SSVC
- Decision:Track
Timeline
- 2024-05-24 CVE Reserved
- 2024-06-19 CVE Published
- 2024-08-20 EPSS Updated
- 2024-12-19 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
CAPEC
References (4)
URL | Tag | Source |
---|---|---|
https://git.kernel.org/stable/c/d3316c8233bb05e0dd855d30aac347bb8ad76ee4 | Vuln. Introduced |
URL | Date | SRC |
---|
URL | Date | SRC |
---|
Affected Vendors, Products, and Versions
Vendor | Product | Version | Other | Status | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.5 < 5.10.88 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.5 < 5.10.88" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.5 < 5.15.11 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.5 < 5.15.11" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.5 < 5.16 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.5 < 5.16" | en |
Affected
|