Use After Free Affecting kernel-debug package, versions *
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Test your applications- Snyk ID SNYK-RHEL7-KERNELDEBUG-6352852
- published 1 Mar 2024
- disclosed 29 Feb 2024
Introduced: 29 Feb 2024
CVE-2021-47068 Open this link in a new tabHow to fix?
There is no fixed version for RHEL:7 kernel-debug.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-debug package and not the kernel-debug package as distributed by RHEL.
See How to fix? for RHEL:7 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
net/nfc: fix use-after-free llcp_sock_bind/connect
Commits 8a4cd82d ("nfc: fix refcount leak in llcp_sock_connect()") and c33b1cc62 ("nfc: fix refcount leak in llcp_sock_bind()") fixed a refcount leak bug in bind/connect but introduced a use-after-free if the same local is assigned to 2 different sockets.
This can be triggered by the following simple program: int sock1 = socket( AF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP ); int sock2 = socket( AF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP ); memset( &addr, 0, sizeof(struct sockaddr_nfc_llcp) ); addr.sa_family = AF_NFC; addr.nfc_protocol = NFC_PROTO_NFC_DEP; bind( sock1, (struct sockaddr*) &addr, sizeof(struct sockaddr_nfc_llcp) ) bind( sock2, (struct sockaddr*) &addr, sizeof(struct sockaddr_nfc_llcp) ) close(sock1); close(sock2);
Fix this by assigning NULL to llcp_sock->local after calling nfc_llcp_local_put.
This addresses CVE-2021-23134.
References
- https://access.redhat.com/security/cve/CVE-2021-47068
- https://git.kernel.org/stable/c/18175fe17ae043a0b81e5d511f8817825784c299
- https://git.kernel.org/stable/c/18ae4a192a4496e48a5490b52812645d2413307c
- https://git.kernel.org/stable/c/26157c82ba756767b2bd66d28a71b1bc454447f6
- https://git.kernel.org/stable/c/374cdde4dcc9c909a60713abdbbf96d5e3e09f91
- https://git.kernel.org/stable/c/48fba458fe54cc2a980a05c13e6c19b8b2cfb610
- https://git.kernel.org/stable/c/6b7021ed36dabf29e56842e3408781cd3b82ef6e
- https://git.kernel.org/stable/c/c61760e6940dd4039a7f5e84a6afc9cdbf4d82b6
- https://git.kernel.org/stable/c/ccddad6dd28530e716448e594c9ca7c76ccd0570
- https://git.kernel.org/stable/c/e32352070bcac22be6ed8ab635debc280bb65b8c