CVE-2021-47238

In the Linux kernel, the following vulnerability has been resolved: net: ipv4: fix memory leak in ip_mc_add1_src BUG: memory leak unreferenced object 0xffff888101bc4c00 (size 32): comm "syz-executor527", pid 360, jiffies 4294807421 (age 19.329s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01 00 00 00 00 00 00 00 ac 14 14 bb 00 00 02 00 ................ backtrace: [<00000000f17c5244>] kmalloc include/linux/slab.h:558 [inline] [<00000000f17c5244>] kzalloc include/linux/slab.h:688 [inline] [<00000000f17c5244>] ip_mc_add1_src net/ipv4/igmp.c:1971 [inline] [<00000000f17c5244>] ip_mc_add_src+0x95f/0xdb0 net/ipv4/igmp.c:2095 [<000000001cb99709>] ip_mc_source+0x84c/0xea0 net/ipv4/igmp.c:2416 [<0000000052cf19ed>] do_ip_setsockopt net/ipv4/ip_sockglue.c:1294 [inline] [<0000000052cf19ed>] ip_setsockopt+0x114b/0x30c0 net/ipv4/ip_sockglue.c:1423 [<00000000477edfbc>] raw_setsockopt+0x13d/0x170 net/ipv4/raw.c:857 [<00000000e75ca9bb>] __sys_setsockopt+0x158/0x270 net/socket.c:2117 [<00000000bdb993a8>] __do_sys_setsockopt net/socket.c:2128 [inline] [<00000000bdb993a8>] __se_sys_setsockopt net/socket.c:2125 [inline] [<00000000bdb993a8>] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2125 [<000000006a1ffdbd>] do_syscall_64+0x40/0x80 arch/x86/entry/common.c:47 [<00000000b11467c4>] entry_SYSCALL_64_after_hwframe+0x44/0xae In commit 24803f38a5c0 ("igmp: do not remove igmp souce list info when set link down"), the ip_mc_clear_src() in ip_mc_destroy_dev() was removed, because it was also called in igmpv3_clear_delrec(). Rough callgraph: inetdev_destroy -> ip_mc_destroy_dev -> igmpv3_clear_delrec -> ip_mc_clear_src -> RCU_INIT_POINTER(dev->ip_ptr, NULL) However, ip_mc_clear_src() called in igmpv3_clear_delrec() doesn't release in_dev->mc_list->sources. And RCU_INIT_POINTER() assigns the NULL to dev->ip_ptr. As a result, in_dev cannot be obtained through inetdev_by_index() and then in_dev->mc_list->sources cannot be released by ip_mc_del1_src() in the sock_close. Rough call sequence goes like: sock_close -> __sock_release -> inet_release -> ip_mc_drop_socket -> inetdev_by_index -> ip_mc_leave_src -> ip_mc_del_src -> ip_mc_del1_src So we still need to call ip_mc_clear_src() in ip_mc_destroy_dev() to free in_dev->mc_list->sources.

CVSS v3 5.5 MEDIUM

5.5^/10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/0dc13e75507faa17ac9f7562b4ef7bf8fcd78422
https://git.kernel.org/stable/c/1e28018b5c83d5073f74a6fb72eabe8370b2f501
https://git.kernel.org/stable/c/3dd2aeac2e9624cff9fa634710837e4f2e352758
https://git.kernel.org/stable/c/6cff57eea3347f79f1867cc53e1093b6614138d8
https://git.kernel.org/stable/c/77de6ee73f54a9a89c0afa0bf4c53b239aa9953a
https://git.kernel.org/stable/c/ac31cc837cafb57a271babad8ccffbf733caa076
https://git.kernel.org/stable/c/d8e2973029b8b2ce477b564824431f3385c77083

Configurations

No configuration.

History

03 Jul 2024, 01:37

Type	Values Removed	Values Added
CWE		CWE-400
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 5.5
Summary		(es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net: ipv4: corrige la pérdida de memoria en ip_mc_add1_src. BUG: pérdida de memoria objeto sin referencia 0xffff888101bc4c00 (tamaño 32): comm "syz-executor527", pid 360, jiffies 4294807421 (edad 19.329s) volcado hexadecimal (primeros 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01 00 00 00 00 00 00 00 ac 14 14 bb 00 00 02 00 ................ backtrace: [<00000000f17c5244>] kmalloc include/linux/slab.h:558 [en línea] [<00000000f17c5244>] kzalloc include/ linux/slab.h:688 [en línea] [<00000000f17c5244>] ip_mc_add1_src net/ipv4/igmp.c:1971 [en línea] [<00000000f17c5244>] ip_mc_add_src+0x95f/0xdb0 net/ipv4/igmp.c:2095 <000000001cb99709 >] ip_mc_source+0x84c/0xea0 net/ipv4/igmp.c:2416 [<0000000052cf19ed>] do_ip_setsockopt net/ipv4/ip_sockglue.c:1294 [en línea] [<0000000052cf19ed>] 0net/ipv4/ip_sockglue. c:1423 [<00000000477edfbc>] raw_setsockopt+0x13d/0x170 net/ipv4/raw.c:857 [<00000000e75ca9bb>] __sys_setsockopt+0x158/0x270 net/socket.c:2117 [<00000000bdb993 a8>] __do_sys_setsockopt net/socket.c :2128 [en línea] [<00000000bdb993a8>] __se_sys_setsockopt net/socket.c:2125 [en línea] [<00000000bdb993a8>] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2125 [<000000006a 1ffdbd>] do_syscall_64+0x40/0x80 arch/ x86/entry/common.c:47 [<00000000b11467c4>] Entry_SYSCALL_64_after_hwframe+0x44/0xae En la confirmación 24803f38a5c0 ("igmp: no eliminar la información de la lista de fuentes de igmp cuando se establece el enlace"), se eliminó ip_mc_clear_src() en ip_mc_destroy_dev() , porque también fue llamado en igmpv3_clear_delrec(). Gráfico de llamada aproximado: inetdev_destroy -> ip_mc_destroy_dev -> igmpv3_clear_delrec -> ip_mc_clear_src -> RCU_INIT_POINTER(dev->ip_ptr, NULL) Sin embargo, ip_mc_clear_src() llamado en igmpv3_clear_delrec() no libera in_dev->mc_list->sources. Y RCU_INIT_POINTER() asigna NULL a dev->ip_ptr. Como resultado, in_dev no se puede obtener a través de inetdev_by_index() y luego in_dev->mc_list->sources no se puede liberar mediante ip_mc_del1_src() en sock_close. La secuencia de llamada aproximada es así: sock_close -> __sock_release -> inet_release -> ip_mc_drop_socket -> inetdev_by_index -> ip_mc_leave_src -> ip_mc_del_src -> ip_mc_del1_src Entonces todavía necesitamos llamar a ip_mc_clear_src() en ip_mc_destroy_dev() para liberar in_dev->mc_list ->fuentes .

21 May 2024, 15:15

Type	Values Removed	Values Added
New CVE

Information

Published : 2024-05-21 15:15

Updated : 2024-07-03 01:37

NVD link : CVE-2021-47238

Mitre link : CVE-2021-47238

CVE.ORG link : CVE-2021-47238

JSON object : View

Products Affected

No product.

CWE

CWE-400

Uncontrolled Resource Consumption

5.5 /10