Re: general protection fault in prepare_to_wait
syzbot has found a reproducer for the following crash on: HEAD commit:23e93c9b2cde Revert "gfs2: read journal in large chunks to.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=14e94014c0 kernel config: https://syzkaller.appspot.com/x/.config?x=ee434566c893c7b1 dashboard link: https://syzkaller.appspot.com/bug?extid=55f9d3e51d49e20b2ce5 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=109c886cc0 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11ed20d0c0 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+55f9d3e51d49e20b2...@syzkaller.appspotmail.com IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_hsr: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready kasan: CONFIG_KASAN_INLINE enabled 8021q: adding VLAN 0 to HW filter on device batadv0 kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: [#1] PREEMPT SMP KASAN CPU: 0 PID: 7785 Comm: syz-executor295 Not tainted 5.0.0-rc6+ #72 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0x8df/0x4700 kernel/locking/lockdep.c:3215 Code: 28 00 00 00 0f 85 35 27 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 dc 27 00 00 49 81 3c 24 20 25 9a 89 0f 84 03 f8 RSP: 0018:888094c6f970 EFLAGS: 00010006 kobject: 'vlan0' (d30c60ff): kobject_add_internal: parent: 'mesh', set: '' RAX: dc00 RBX: RCX: RDX: 0003 RSI: RDI: 0018 RBP: 888094c6fb40 R08: 0001 R09: 0001 R10: R11: 0001 R12: 0018 R13: 0001 R14: R15: 88808c0f00c0 FS: 7f9abeeec700() GS:8880ae80() knlGS: 8021q: adding VLAN 0 to HW filter on device batadv0 CS: 0010 DS: ES: CR0: 80050033 kobject: 'vlan0' (a54e32cc): kobject_add_internal: parent: 'mesh', set: '' CR2: 004d0910 CR3: 906d2000 CR4: 001406f0 DR0: DR1: DR2: DR3: DR6: fffe0ff0 DR7: 0400 8021q: adding VLAN 0 to HW filter on device batadv0 Call Trace: kobject: 'vlan0' (16be0e34): kobject_add_internal: parent: 'mesh', set: '' lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3841 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152 prepare_to_wait+0x7c/0x300 kernel/sched/wait.c:230 nr_accept+0x239/0x790 net/netrom/af_netrom.c:796 __sys_accept4+0x350/0x6a0 net/socket.c:1588 __do_sys_accept net/socket.c:1629 [inline] __se_sys_accept net/socket.c:1626 [inline] __x64_sys_accept+0x75/0xb0 net/socket.c:1626 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x449489 Code: e8 7c e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 1b 05 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:7f9abeeebcc8 EFLAGS: 0246 ORIG_RAX: 002b RAX: ffda RBX: 006dfc68 RCX: 00449489 RDX: RSI: RDI: 0004 RBP: 006dfc60 R08: 7f9abeeec700 R09: R10: 7f9abeeec700 R11: 0246 R12: 006dfc6c R13: 7ffe8979730f R14: 7f9abeeec9c0 R15: 0002 Modules linked in: ---[ end trace 91ccd60fc619e2e6 ]--- RIP: 0010:__lock_acquire+0x8df/0x4700 kernel/locking/lockdep.c:3215 Code: 28 00 00 00 0f 85 35 27 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 dc 27 00 00 49 81 3c 24 20 25 9a 89 0f 84 03 f8 RSP: 0018:888094c6f970 EFLAGS: 00010006 RAX: dc00 RBX: RCX: RDX: 0003 RSI: RDI: 0018 RBP: 888094c6fb40 R08: 0001 R09: 0001 R10: R11: 0001 R12: 0018 R13: 0001 R14: R15: 88808c0f00c0 FS: 7f9abeeec700() GS:8880ae80() knlGS: CS: 0010 DS: ES: CR0: 80050033 CR2: 004d0910 CR3: 906d2000 CR4: 001406f0 DR0: DR1: DR2: DR3: DR6: fffe0ff0 DR7: 0400
Re: KASAN: use-after-free Read in lock_sock_nested
syzbot has found a reproducer for the following crash on: HEAD commit:b3418f8bddf4 Add linux-next specific files for 20190214 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=14f6304740 kernel config: https://syzkaller.appspot.com/x/.config?x=8a3a37525a677c71 dashboard link: https://syzkaller.appspot.com/bug?extid=500c69d1e21d970e461b compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14b08da740 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+500c69d1e21d970e4...@syzkaller.appspotmail.com == BUG: KASAN: use-after-free in __lock_acquire+0x3150/0x4710 kernel/locking/lockdep.c:3200 Read of size 8 at addr 8880195faa60 by task syz-executor.4/7495 CPU: 1 PID: 7495 Comm: syz-executor.4 Not tainted 5.0.0-rc6-next-20190214 #35 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 __lock_acquire+0x3150/0x4710 kernel/locking/lockdep.c:3200 lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3833 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x33/0x50 kernel/locking/spinlock.c:168 spin_lock_bh include/linux/spinlock.h:334 [inline] lock_sock_nested+0x41/0x120 net/core/sock.c:2878 lock_sock include/net/sock.h:1507 [inline] nr_accept+0x200/0x790 net/netrom/af_netrom.c:808 __sys_accept4+0x350/0x6a0 net/socket.c:1610 __do_sys_accept net/socket.c:1651 [inline] __se_sys_accept net/socket.c:1648 [inline] __x64_sys_accept+0x75/0xb0 net/socket.c:1648 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e29 Code: ad b8 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 b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:7f16cb51ec78 EFLAGS: 0246 ORIG_RAX: 002b RAX: ffda RBX: 0003 RCX: 00457e29 RDX: RSI: RDI: 0004 RBP: 0073bfa0 R08: R09: R10: R11: 0246 R12: 7f16cb51f6d4 R13: 004bdbf0 R14: 004cde80 R15: Allocated by task 7492: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_kmalloc mm/kasan/common.c:497 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:511 __do_kmalloc mm/slab.c:3721 [inline] __kmalloc+0x15c/0x740 mm/slab.c:3730 kmalloc include/linux/slab.h:553 [inline] sk_prot_alloc+0x19c/0x2e0 net/core/sock.c:1573 sk_alloc+0x39/0xf70 net/core/sock.c:1627 nr_create+0xb9/0x5e0 net/netrom/af_netrom.c:436 __sock_create+0x3e6/0x750 net/socket.c:1297 sock_create net/socket.c:1337 [inline] __sys_socket+0x103/0x220 net/socket.c:1367 __do_sys_socket net/socket.c:1376 [inline] __se_sys_socket net/socket.c:1374 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1374 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 7491: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459 kasan_slab_free+0xe/0x10 mm/kasan/common.c:467 __cache_free mm/slab.c:3491 [inline] kfree+0xcf/0x230 mm/slab.c:3816 sk_prot_free net/core/sock.c:1610 [inline] __sk_destruct+0x4f1/0x6d0 net/core/sock.c:1692 sk_destruct+0x7b/0x90 net/core/sock.c:1700 __sk_free+0xce/0x300 net/core/sock.c:1711 sk_free+0x42/0x50 net/core/sock.c:1722 sock_put include/net/sock.h:1708 [inline] nr_release+0x337/0x3c0 net/netrom/af_netrom.c:557 __sock_release+0xd3/0x250 net/socket.c:579 sock_close+0x1b/0x30 net/socket.c:1161 __fput+0x2e5/0x8d0 fs/file_table.c:278 fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x14a/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at 8880195fa9c0 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 160 bytes inside of 2048-byte region [8880195fa9c0, 8880195fb1c0) The buggy address belongs to the page: page:ea
[PATCH AUTOSEL 4.20 59/77] ax25: fix possible use-after-free
From: Eric Dumazet [ Upstream commit 63530aba7826a0f8e129874df9c4d264f9db3f9e ] syzbot found that ax25 routes where not properly protected against concurrent use [1]. In this particular report the bug happened while copying ax25->digipeat. Fix this problem by making sure we call ax25_get_route() while ax25_route_lock is held, so that no modification could happen while using the route. The current two ax25_get_route() callers do not sleep, so this change should be fine. Once we do that, ax25_get_route() no longer needs to grab a reference on the found route. [1] ax25_connect(): syz-executor0 uses autobind, please contact jreu...@yaina.de BUG: KASAN: use-after-free in memcpy include/linux/string.h:352 [inline] BUG: KASAN: use-after-free in kmemdup+0x42/0x60 mm/util.c:113 Read of size 66 at addr 888066641a80 by task syz-executor2/531 ax25_connect(): syz-executor0 uses autobind, please contact jreu...@yaina.de CPU: 1 PID: 531 Comm: syz-executor2 Not tainted 5.0.0-rc2+ #10 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+0x1db/0x2d0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x123/0x190 mm/kasan/generic.c:191 memcpy+0x24/0x50 mm/kasan/common.c:130 memcpy include/linux/string.h:352 [inline] kmemdup+0x42/0x60 mm/util.c:113 kmemdup include/linux/string.h:425 [inline] ax25_rt_autobind+0x25d/0x750 net/ax25/ax25_route.c:424 ax25_connect.cold+0x30/0xa4 net/ax25/af_ax25.c:1224 __sys_connect+0x357/0x490 net/socket.c:1664 __do_sys_connect net/socket.c:1675 [inline] __se_sys_connect net/socket.c:1672 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1672 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458099 Code: 6d b7 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:7f870ee22c78 EFLAGS: 0246 ORIG_RAX: 002a RAX: ffda RBX: 0003 RCX: 00458099 RDX: 0048 RSI: 2080 RDI: 0005 RBP: 0073bf00 R08: R09: ax25_connect(): syz-executor4 uses autobind, please contact jreu...@yaina.de R10: R11: 0246 R12: 7f870ee236d4 R13: 004be48e R14: 004ce9a8 R15: Allocated by task 526: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:496 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504 ax25_connect(): syz-executor5 uses autobind, please contact jreu...@yaina.de kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609 kmalloc include/linux/slab.h:545 [inline] ax25_rt_add net/ax25/ax25_route.c:95 [inline] ax25_rt_ioctl+0x3b9/0x1270 net/ax25/ax25_route.c:233 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763 sock_do_ioctl+0xe2/0x400 net/socket.c:950 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe ax25_connect(): syz-executor5 uses autobind, please contact jreu...@yaina.de Freed by task 550: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466 __cache_free mm/slab.c:3487 [inline] kfree+0xcf/0x230 mm/slab.c:3806 ax25_rt_add net/ax25/ax25_route.c:92 [inline] ax25_rt_ioctl+0x304/0x1270 net/ax25/ax25_route.c:233 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763 sock_do_ioctl+0xe2/0x400 net/socket.c:950 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at 888066641a80 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of 96-byte region [888066641a80, 888066641ae0) The buggy address belongs to the page: page:ea0001999040 count:1 mapcount:0 mapping:88812c3f04c0 index:0x0 flags:
[PATCH AUTOSEL 4.14 32/40] ax25: fix possible use-after-free
From: Eric Dumazet [ Upstream commit 63530aba7826a0f8e129874df9c4d264f9db3f9e ] syzbot found that ax25 routes where not properly protected against concurrent use [1]. In this particular report the bug happened while copying ax25->digipeat. Fix this problem by making sure we call ax25_get_route() while ax25_route_lock is held, so that no modification could happen while using the route. The current two ax25_get_route() callers do not sleep, so this change should be fine. Once we do that, ax25_get_route() no longer needs to grab a reference on the found route. [1] ax25_connect(): syz-executor0 uses autobind, please contact jreu...@yaina.de BUG: KASAN: use-after-free in memcpy include/linux/string.h:352 [inline] BUG: KASAN: use-after-free in kmemdup+0x42/0x60 mm/util.c:113 Read of size 66 at addr 888066641a80 by task syz-executor2/531 ax25_connect(): syz-executor0 uses autobind, please contact jreu...@yaina.de CPU: 1 PID: 531 Comm: syz-executor2 Not tainted 5.0.0-rc2+ #10 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+0x1db/0x2d0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x123/0x190 mm/kasan/generic.c:191 memcpy+0x24/0x50 mm/kasan/common.c:130 memcpy include/linux/string.h:352 [inline] kmemdup+0x42/0x60 mm/util.c:113 kmemdup include/linux/string.h:425 [inline] ax25_rt_autobind+0x25d/0x750 net/ax25/ax25_route.c:424 ax25_connect.cold+0x30/0xa4 net/ax25/af_ax25.c:1224 __sys_connect+0x357/0x490 net/socket.c:1664 __do_sys_connect net/socket.c:1675 [inline] __se_sys_connect net/socket.c:1672 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1672 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458099 Code: 6d b7 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:7f870ee22c78 EFLAGS: 0246 ORIG_RAX: 002a RAX: ffda RBX: 0003 RCX: 00458099 RDX: 0048 RSI: 2080 RDI: 0005 RBP: 0073bf00 R08: R09: ax25_connect(): syz-executor4 uses autobind, please contact jreu...@yaina.de R10: R11: 0246 R12: 7f870ee236d4 R13: 004be48e R14: 004ce9a8 R15: Allocated by task 526: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:496 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504 ax25_connect(): syz-executor5 uses autobind, please contact jreu...@yaina.de kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609 kmalloc include/linux/slab.h:545 [inline] ax25_rt_add net/ax25/ax25_route.c:95 [inline] ax25_rt_ioctl+0x3b9/0x1270 net/ax25/ax25_route.c:233 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763 sock_do_ioctl+0xe2/0x400 net/socket.c:950 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe ax25_connect(): syz-executor5 uses autobind, please contact jreu...@yaina.de Freed by task 550: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466 __cache_free mm/slab.c:3487 [inline] kfree+0xcf/0x230 mm/slab.c:3806 ax25_rt_add net/ax25/ax25_route.c:92 [inline] ax25_rt_ioctl+0x304/0x1270 net/ax25/ax25_route.c:233 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763 sock_do_ioctl+0xe2/0x400 net/socket.c:950 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at 888066641a80 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of 96-byte region [888066641a80, 888066641ae0) The buggy address belongs to the page: page:ea0001999040 count:1 mapcount:0 mapping:88812c3f04c0 index:0x0 flags:
[PATCH AUTOSEL 4.9 20/27] ax25: fix possible use-after-free
From: Eric Dumazet [ Upstream commit 63530aba7826a0f8e129874df9c4d264f9db3f9e ] syzbot found that ax25 routes where not properly protected against concurrent use [1]. In this particular report the bug happened while copying ax25->digipeat. Fix this problem by making sure we call ax25_get_route() while ax25_route_lock is held, so that no modification could happen while using the route. The current two ax25_get_route() callers do not sleep, so this change should be fine. Once we do that, ax25_get_route() no longer needs to grab a reference on the found route. [1] ax25_connect(): syz-executor0 uses autobind, please contact jreu...@yaina.de BUG: KASAN: use-after-free in memcpy include/linux/string.h:352 [inline] BUG: KASAN: use-after-free in kmemdup+0x42/0x60 mm/util.c:113 Read of size 66 at addr 888066641a80 by task syz-executor2/531 ax25_connect(): syz-executor0 uses autobind, please contact jreu...@yaina.de CPU: 1 PID: 531 Comm: syz-executor2 Not tainted 5.0.0-rc2+ #10 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+0x1db/0x2d0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x123/0x190 mm/kasan/generic.c:191 memcpy+0x24/0x50 mm/kasan/common.c:130 memcpy include/linux/string.h:352 [inline] kmemdup+0x42/0x60 mm/util.c:113 kmemdup include/linux/string.h:425 [inline] ax25_rt_autobind+0x25d/0x750 net/ax25/ax25_route.c:424 ax25_connect.cold+0x30/0xa4 net/ax25/af_ax25.c:1224 __sys_connect+0x357/0x490 net/socket.c:1664 __do_sys_connect net/socket.c:1675 [inline] __se_sys_connect net/socket.c:1672 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1672 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458099 Code: 6d b7 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:7f870ee22c78 EFLAGS: 0246 ORIG_RAX: 002a RAX: ffda RBX: 0003 RCX: 00458099 RDX: 0048 RSI: 2080 RDI: 0005 RBP: 0073bf00 R08: R09: ax25_connect(): syz-executor4 uses autobind, please contact jreu...@yaina.de R10: R11: 0246 R12: 7f870ee236d4 R13: 004be48e R14: 004ce9a8 R15: Allocated by task 526: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:496 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504 ax25_connect(): syz-executor5 uses autobind, please contact jreu...@yaina.de kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609 kmalloc include/linux/slab.h:545 [inline] ax25_rt_add net/ax25/ax25_route.c:95 [inline] ax25_rt_ioctl+0x3b9/0x1270 net/ax25/ax25_route.c:233 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763 sock_do_ioctl+0xe2/0x400 net/socket.c:950 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe ax25_connect(): syz-executor5 uses autobind, please contact jreu...@yaina.de Freed by task 550: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466 __cache_free mm/slab.c:3487 [inline] kfree+0xcf/0x230 mm/slab.c:3806 ax25_rt_add net/ax25/ax25_route.c:92 [inline] ax25_rt_ioctl+0x304/0x1270 net/ax25/ax25_route.c:233 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763 sock_do_ioctl+0xe2/0x400 net/socket.c:950 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at 888066641a80 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of 96-byte region [888066641a80, 888066641ae0) The buggy address belongs to the page: page:ea0001999040 count:1 mapcount:0 mapping:88812c3f04c0 index:0x0 flags:
[PATCH AUTOSEL 4.4 16/20] ax25: fix possible use-after-free
From: Eric Dumazet [ Upstream commit 63530aba7826a0f8e129874df9c4d264f9db3f9e ] syzbot found that ax25 routes where not properly protected against concurrent use [1]. In this particular report the bug happened while copying ax25->digipeat. Fix this problem by making sure we call ax25_get_route() while ax25_route_lock is held, so that no modification could happen while using the route. The current two ax25_get_route() callers do not sleep, so this change should be fine. Once we do that, ax25_get_route() no longer needs to grab a reference on the found route. [1] ax25_connect(): syz-executor0 uses autobind, please contact jreu...@yaina.de BUG: KASAN: use-after-free in memcpy include/linux/string.h:352 [inline] BUG: KASAN: use-after-free in kmemdup+0x42/0x60 mm/util.c:113 Read of size 66 at addr 888066641a80 by task syz-executor2/531 ax25_connect(): syz-executor0 uses autobind, please contact jreu...@yaina.de CPU: 1 PID: 531 Comm: syz-executor2 Not tainted 5.0.0-rc2+ #10 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+0x1db/0x2d0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x123/0x190 mm/kasan/generic.c:191 memcpy+0x24/0x50 mm/kasan/common.c:130 memcpy include/linux/string.h:352 [inline] kmemdup+0x42/0x60 mm/util.c:113 kmemdup include/linux/string.h:425 [inline] ax25_rt_autobind+0x25d/0x750 net/ax25/ax25_route.c:424 ax25_connect.cold+0x30/0xa4 net/ax25/af_ax25.c:1224 __sys_connect+0x357/0x490 net/socket.c:1664 __do_sys_connect net/socket.c:1675 [inline] __se_sys_connect net/socket.c:1672 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1672 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458099 Code: 6d b7 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:7f870ee22c78 EFLAGS: 0246 ORIG_RAX: 002a RAX: ffda RBX: 0003 RCX: 00458099 RDX: 0048 RSI: 2080 RDI: 0005 RBP: 0073bf00 R08: R09: ax25_connect(): syz-executor4 uses autobind, please contact jreu...@yaina.de R10: R11: 0246 R12: 7f870ee236d4 R13: 004be48e R14: 004ce9a8 R15: Allocated by task 526: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:496 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504 ax25_connect(): syz-executor5 uses autobind, please contact jreu...@yaina.de kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609 kmalloc include/linux/slab.h:545 [inline] ax25_rt_add net/ax25/ax25_route.c:95 [inline] ax25_rt_ioctl+0x3b9/0x1270 net/ax25/ax25_route.c:233 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763 sock_do_ioctl+0xe2/0x400 net/socket.c:950 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe ax25_connect(): syz-executor5 uses autobind, please contact jreu...@yaina.de Freed by task 550: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466 __cache_free mm/slab.c:3487 [inline] kfree+0xcf/0x230 mm/slab.c:3806 ax25_rt_add net/ax25/ax25_route.c:92 [inline] ax25_rt_ioctl+0x304/0x1270 net/ax25/ax25_route.c:233 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763 sock_do_ioctl+0xe2/0x400 net/socket.c:950 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at 888066641a80 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of 96-byte region [888066641a80, 888066641ae0) The buggy address belongs to the page: page:ea0001999040 count:1 mapcount:0 mapping:88812c3f04c0 index:0x0 flags:
