CVE-2021-47068

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxa1cdd18c49d23ec38097ac2c5b0d761146fc0109 < 26157c82ba756767b2bd66d28a71b1bc454447f6affected
LinuxLinux18013007b596771bf5f5e7feee9586fb0386ad14 < ccddad6dd28530e716448e594c9ca7c76ccd0570affected
LinuxLinux538a6ff11516d38a61e237d2d2dc04c30c845fbe < 18ae4a192a4496e48a5490b52812645d2413307caffected
LinuxLinuxadbb1d218c5f56dbae052765da83c0f57fce2a31 < 48fba458fe54cc2a980a05c13e6c19b8b2cfb610affected
LinuxLinuxc89903c9eff219a4695e63715cf922748d743f65 < e32352070bcac22be6ed8ab635debc280bb65b8caffected
LinuxLinux6fb003e5ae18d8cda4c8a1175d9dd8db12bec049 < 6b7021ed36dabf29e56842e3408781cd3b82ef6eaffected
LinuxLinux8c9e4971e142e2899606a2490b77a1208c1f4638 < 374cdde4dcc9c909a60713abdbbf96d5e3e09f91affected
LinuxLinuxc33b1cc62ac05c1dbb1cdafe2eb66da01c76ca8d < 18175fe17ae043a0b81e5d511f8817825784c299affected
LinuxLinuxc33b1cc62ac05c1dbb1cdafe2eb66da01c76ca8d < c61760e6940dd4039a7f5e84a6afc9cdbf4d82b6affected
LinuxLinux4.4.267 < 4.4.269affected
LinuxLinux4.9.267 < 4.9.269affected
LinuxLinux4.14.231 < 4.14.233affected
LinuxLinux4.19.187 < 4.19.191affected
LinuxLinux5.4.112 < 5.4.119affected
LinuxLinux5.10.30 < 5.10.37affected
LinuxLinux5.11.14 < 5.11.21affected
LinuxLinux5.12affected
LinuxLinux0 < 5.12unaffected
LinuxLinux4.4.269 <= 4.4.*unaffected
LinuxLinux4.9.269 <= 4.9.*unaffected
LinuxLinux4.14.233 <= 4.14.*unaffected
LinuxLinux4.19.191 <= 4.19.*unaffected
LinuxLinux5.4.119 <= 5.4.*unaffected
LinuxLinux5.10.37 <= 5.10.*unaffected
LinuxLinux5.11.21 <= 5.11.*unaffected
LinuxLinux5.12.4 <= 5.12.*unaffected
LinuxLinux5.13 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

CVE Program Container

Additional References

References