cbcvebase.
CVE-2021-47394
published 2024-05-21

CVE-2021-47394: In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: unlink table before deleting it syzbot reports following UAF: BUG…

PriorityP337high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.23%
14.3th percentile
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: unlink table before deleting it syzbot reports following UAF: BUG: KASAN: use-after-free in memcmp+0x18f/0x1c0 lib/string.c:955 nla_strcmp+0xf2/0x130 lib/nlattr.c:836 nft_table_lookup.part.0+0x1a2/0x460 net/netfilter/nf_tables_api.c:570 nft_table_lookup net/netfilter/nf_tables_api.c:4064 [inline] nf_tables_getset+0x1b3/0x860 net/netfilter/nf_tables_api.c:4064 nfnetlink_rcv_msg+0x659/0x13f0 net/netfilter/nfnetlink.c:285 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504 Problem is that all get operations are lockless, so the commit_mutex held by nft_rcv_nl_event() isn't enough to stop a parallel GET request from doing read-accesses to the table object even after synchronize_rcu(). To avoid this, unlink the table first and store the table objects in on-stack scratch space.

Affected

9 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 5.14.12-1 (bookworm)linux 5.14.12-1 (bookworm)
linuxlinux
linuxlinux>= 6001a930ce0378b62210d4f83583fc88a903d89d < f65c73d3aabb87d4353e0bc4a718b5ae8c43fd04f65c73d3aabb87d4353e0bc4a718b5ae8c43fd04
linuxlinux>= 6001a930ce0378b62210d4f83583fc88a903d89d < a499b03bf36b0c2e3b958a381d828678ab0ffc5ea499b03bf36b0c2e3b958a381d828678ab0ffc5e
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.14.12-15.14.12-1
linuxlinux_kernel>= 0 < 5.14.12-15.14.12-1
linuxlinux_kernel>= 0 < 5.14.12-15.14.12-1
linuxlinux_kernel>= 5.12 < 5.14.105.14.10

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.8HIGH
vendor_debian7.8HIGH
vendor_redhat7.8HIGH
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