CVE-2021-47115 Information

Mar 16, 2024 cve

Description

In the Linux kernel the following vulnerability has been resolved:

nfc: fix NULL ptr dereference in llcp_sock_getname() after failed connect

It’s possible to trigger NULL pointer dereference by local unprivileged user when calling getsockname() after failed bind() (e.g. the bind fails because LLCP_SAP_MAX used as SAP):

BUG: kernel NULL pointer dereference address: 0000000000000000 CPU: 1 PID: 426 Comm: llcp_sock_getna Not tainted 5.13.0-rc2-next-20210521+ 9 Hardware name: QEMU Standard PC (i440FX + PIIX 1996) BIOS 1.14.0-1 04/01/2014 Call Trace: llcp_sock_getname+0xb1/0xe0 __sys_getpeername+0x95/0xc0 ? lockdep_hardirqs_on_prepare+0xd5/0x180 ? syscall_enter_from_user_mode+0x1c/0x40 __x64_sys_getpeername+0x11/0x20 do_syscall_64+0x36/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xae

This can be reproduced with Syzkaller C repro (bind followed by getpeername): https://syzkaller.appspot.com/x/repro.c?x=14def446e00000

Reference

https://git.kernel.org/stable/c/eb6875d48590d8e564092e831ff07fa384d7e477 https://git.kernel.org/stable/c/39c15bd2e5d11bcf7f4c3dba2aad9e1e110a5d94 https://git.kernel.org/stable/c/ffff05b9ee5c74c04bba2801c1f99b31975d74d9 https://git.kernel.org/stable/c/93e4ac2a9979a9a4ecc158409ed9c3044dc0ae1f https://git.kernel.org/stable/c/5d4c4b06ed9fb7a69d0b2e2a73fc73226d25ab70 https://git.kernel.org/stable/c/48ee0db61c8299022ec88c79ad137f290196cac2 https://git.kernel.org/stable/c/0c4559736d9a4ec1ca58ba98ca34e7c4da4c422b https://git.kernel.org/stable/c/4ac06a1e013cf5fdd963317ffd3b968560f33bba

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