"value":"In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: add sanity checks to rx zerocopy\n\nTCP rx zerocopy intent is to map pages initially allocated\nfrom NIC drivers, not pages owned by a fs.\n\nThis patch adds to can_map_frag() these additional checks:\n\n- Page must not be a compound one.\n- page->mapping must be NULL.\n\nThis fixes the panic reported by ZhangPeng.\n\nsyzbot was able to loopback packets built with sendfile(),\nmapping pages owned by an ext4 file to TCP rx zerocopy.\n\nr3 = socket$inet_tcp(0x2, 0x1, 0x0)\nmmap(&(0x7f0000ff9000/0x4000)=nil, 0x4000, 0x0, 0x12, r3, 0x0)\nr4 = socket$inet_tcp(0x2, 0x1, 0x0)\nbind$inet(r4, &(0x7f0000000000)={0x2, 0x4e24, @multicast1}, 0x10)\nconnect$inet(r4, &(0x7f00000006c0)={0x2, 0x4e24, @empty}, 0x10)\nr5 = openat$dir(0xffffffffffffff9c, &(0x7f00000000c0)='./file0\\x00',\n 0x181e42, 0x0)\nfallocate(r5, 0x0, 0x0, 0x85b8)\nsendfile(r4, r5, 0x0, 0x8ba0)\ngetsockopt$inet_tcp_TCP_ZEROCOPY_RECEIVE(r4, 0x6, 0x23,\n &(0x7f00000001c0)={&(0x7f0000ffb000/0x3000)=nil, 0x3000, 0x0, 0x0, 0x0,\n 0x0, 0x0, 0x0, 0x0}, &(0x7f0000000440)=0x40)\nr6 = openat$dir(0xffffffffffffff9c, &(0x7f00000000c0)='./file0\\x00',\n 0x181e42, 0x0)"