================================================================== BUG: KASAN: use-after-free in ethnl_bitmap32_not_zero net/ethtool/bitset.c:112 [inline] BUG: KASAN: use-after-free in ethnl_compact_sanity_checks net/ethtool/bitset.c:529 [inline] BUG: KASAN: use-after-free in ethnl_update_bitset32.part.0+0x8db/0x1820 net/ethtool/bitset.c:572 Read of size 4 at addr ffff8880a6fb343c by task syz-executor.2/16480 CPU: 1 PID: 16480 Comm: syz-executor.2 Not tainted 5.6.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x32 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:641 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:134 ethnl_bitmap32_not_zero net/ethtool/bitset.c:112 [inline] ethnl_compact_sanity_checks net/ethtool/bitset.c:529 [inline] ethnl_update_bitset32.part.0+0x8db/0x1820 net/ethtool/bitset.c:572 ethnl_update_bitset32 net/ethtool/bitset.c:562 [inline] ethnl_update_bitset+0x4d/0x67 net/ethtool/bitset.c:734 ethnl_update_linkmodes net/ethtool/linkmodes.c:303 [inline] ethnl_set_linkmodes+0x461/0xc30 net/ethtool/linkmodes.c:357 genl_family_rcv_msg_doit net/netlink/genetlink.c:672 [inline] genl_family_rcv_msg net/netlink/genetlink.c:717 [inline] genl_rcv_msg+0x67d/0xea0 net/netlink/genetlink.c:734 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2478 genl_rcv+0x29/0x40 net/netlink/genetlink.c:745 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:672 ____sys_sendmsg+0x753/0x880 net/socket.c:2343 ___sys_sendmsg+0x100/0x170 net/socket.c:2397 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430 __do_sys_sendmsg net/socket.c:2439 [inline] __se_sys_sendmsg net/socket.c:2437 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c479 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f021a129c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f021a12a6d4 RCX: 000000000045c479 RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000003 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000904 R14: 00000000004d4ff0 R15: 000000000076bf2c Allocated by task 10698: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:515 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:488 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529 __do_kmalloc_node mm/slab.c:3616 [inline] __kmalloc_node+0x4e/0x70 mm/slab.c:3623 kmalloc_node include/linux/slab.h:578 [inline] kvmalloc_node+0x68/0x100 mm/util.c:574 kvmalloc include/linux/mm.h:645 [inline] alloc_fdtable+0x142/0x290 fs/file.c:120 dup_fd+0x782/0xb70 fs/file.c:310 copy_files kernel/fork.c:1466 [inline] copy_process+0x1e74/0x7290 kernel/fork.c:2069 _do_fork+0x146/0x1090 kernel/fork.c:2430 __do_sys_clone kernel/fork.c:2585 [inline] __se_sys_clone kernel/fork.c:2566 [inline] __x64_sys_clone+0x19a/0x260 kernel/fork.c:2566 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 15433: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:476 kasan_slab_free+0xe/0x10 mm/kasan/common.c:485 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x2c0 mm/slab.c:3757 kvfree+0x4a/0x60 mm/util.c:603 __free_fdtable+0x5a/0x80 fs/file.c:32 put_files_struct fs/file.c:420 [inline] put_files_struct+0x253/0x2f0 fs/file.c:413 exit_files+0x83/0xb0 fs/file.c:445 do_exit+0xb77/0x2f50 kernel/exit.c:796 do_group_exit+0x135/0x360 kernel/exit.c:899 __do_sys_exit_group kernel/exit.c:910 [inline] __se_sys_exit_group kernel/exit.c:908 [inline] __x64_sys_exit_group+0x44/0x50 kernel/exit.c:908 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a6fb3400 which belongs to the cache kmalloc-96(17:syz0) of size 96 The buggy address is located 60 bytes inside of 96-byte region [ffff8880a6fb3400, ffff8880a6fb3460) The buggy address belongs to the page: page:ffffea00029becc0 refcount:1 mapcount:0 mapping:ffff888096411e00 index:0xffff8880a6fb3280 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffff8880a2d66238 ffffea00023df548 ffff888096411e00 raw: ffff8880a6fb3280 ffff8880a6fb3000 000000010000001d 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a6fb3300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880a6fb3380: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc >ffff8880a6fb3400: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8880a6fb3480: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880a6fb3500: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc ==================================================================