جزئیات آسیب‌پذیری

In the Linux kernel, the following vulnerability has been resolved: netfilter: ebtables: terminate table name before find_table_lock() update_counters() and compat_update_counters() forward a user-supplied 32-byte table name to find_table_lock() without NUL-terminating it. On a lookup miss, find_inlist_lock() calls try_then_request_module(..., "%s%s", "ebtable_", name), and vsnprintf() reads past the name field and the stack object until it hits a zero byte. BUG: KASAN: stack-out-of-bounds in string (lib/vsprintf.c:648 lib/vsprintf.c:730) Read of size 1 at addr ffff8880119dfb20 by task exploit/147 Call Trace: ... string (lib/vsprintf.c:648 lib/vsprintf.c:730) vsnprintf (lib/vsprintf.c:2945) __request_module (kernel/module/kmod.c:150) do_update_counters.isra.0 (net/bridge/netfilter/ebtables.c:371 net/bridge/netfilter/ebtables.c:380) update_counters (net/bridge/netfilter/ebtables.c:1440) do_ebt_set_ctl (net/bridge/netfilter/ebtables.c:2573) nf_setsockopt (net/netfilter/nf_sockopt.c:101) ip_setsockopt (net/ipv4/ip_sockglue.c:1424) raw_setsockopt (net/ipv4/raw.c:847) __sys_setsockopt (net/socket.c:2393) ... compat_do_replace() shares the same unterminated name via compat_copy_ebt_replace_from_user(); terminate it there too so all find_table_lock() callers behave alike. The other callers already terminate the name after the copy.

• https://git.kernel.org/stable/c/4c046ca4e35a83ea32f6e748f54139f5fe2a1d01
• https://git.kernel.org/stable/c/ab63ccefb9c71627f957a0724c2b9ebc869c6f20
• https://git.kernel.org/stable/c/c6f539311e58e76aa96feef0f1572b13a564f8a2
• https://git.kernel.org/stable/c/2664f537ca5bcb2ef3fac2683dcca602e51fad24
• https://git.kernel.org/stable/c/7436da6c1bc44654b7f11a17e746f6999fd37250
• https://git.kernel.org/stable/c/6fe8d3cecd20bfaaaf440db3a06ba674d2f2e322
• https://git.kernel.org/stable/c/b6183b1b88a722b6d8ea0cecc99eba168a15e0be
• https://git.kernel.org/stable/c/a622d2e9608c9dff47fc2e5759ac7aa3a836b45d
• https://cert-portal.siemens.com/productcert/html/ssa-019113.html
• https://cert-portal.siemens.com/productcert/html/ssa-457936.html