CVE-2021-47238
Linux Kernel: Memory Leak in igmp
Description
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.
INFO
Published Date :
May 21, 2024, 3:15 p.m.
Last Modified :
July 3, 2024, 1:37 a.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
3.6
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
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information, practical solutions, and valuable tools related to
CVE-2021-47238.
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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The following list is the news that have been mention
CVE-2021-47238 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47238 vulnerability over time.
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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CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 03, 2024
Action Type Old Value New Value Added CWE CISA-ADP CWE-400 Added CVSS V3.1 CISA-ADP AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 21, 2024
Action Type Old Value New Value Added Description 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. Added Reference kernel.org https://git.kernel.org/stable/c/0dc13e75507faa17ac9f7562b4ef7bf8fcd78422 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/6cff57eea3347f79f1867cc53e1093b6614138d8 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/1e28018b5c83d5073f74a6fb72eabe8370b2f501 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/3dd2aeac2e9624cff9fa634710837e4f2e352758 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/ac31cc837cafb57a271babad8ccffbf733caa076 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/77de6ee73f54a9a89c0afa0bf4c53b239aa9953a [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/d8e2973029b8b2ce477b564824431f3385c77083 [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47238 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-47238
weaknesses.