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authorYueHaibing <yuehaibing@huawei.com>2019-03-01 10:57:57 +0800
committerDavid S. Miller <davem@davemloft.net>2019-03-03 13:01:49 -0800
commit6377f787aeb945cae7abbb6474798de129e1f3ac (patch)
tree935843fcf2a3449d2915c4620da0140446cc7b3d
parente2bcd8b0ce6ee3410665765db0d44dd8b7e3b348 (diff)
appletalk: Fix use-after-free in atalk_proc_exit
KASAN report this: BUG: KASAN: use-after-free in pde_subdir_find+0x12d/0x150 fs/proc/generic.c:71 Read of size 8 at addr ffff8881f41fe5b0 by task syz-executor.0/2806 CPU: 0 PID: 2806 Comm: syz-executor.0 Not tainted 5.0.0-rc7+ #45 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xfa/0x1ce lib/dump_stack.c:113 print_address_description+0x65/0x270 mm/kasan/report.c:187 kasan_report+0x149/0x18d mm/kasan/report.c:317 pde_subdir_find+0x12d/0x150 fs/proc/generic.c:71 remove_proc_entry+0xe8/0x420 fs/proc/generic.c:667 atalk_proc_exit+0x18/0x820 [appletalk] atalk_exit+0xf/0x5a [appletalk] __do_sys_delete_module kernel/module.c:1018 [inline] __se_sys_delete_module kernel/module.c:961 [inline] __x64_sys_delete_module+0x3dc/0x5e0 kernel/module.c:961 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x462e99 Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb2de6b9c58 EFLAGS: 00000246 ORIG_RAX: 00000000000000b0 RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462e99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb2de6ba6bc R13: 00000000004bccaa R14: 00000000006f6bc8 R15: 00000000ffffffff Allocated by task 2806: set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc.constprop.3+0xa0/0xd0 mm/kasan/common.c:496 slab_post_alloc_hook mm/slab.h:444 [inline] slab_alloc_node mm/slub.c:2739 [inline] slab_alloc mm/slub.c:2747 [inline] kmem_cache_alloc+0xcf/0x250 mm/slub.c:2752 kmem_cache_zalloc include/linux/slab.h:730 [inline] __proc_create+0x30f/0xa20 fs/proc/generic.c:408 proc_mkdir_data+0x47/0x190 fs/proc/generic.c:469 0xffffffffc10c01bb 0xffffffffc10c0166 do_one_initcall+0xfa/0x5ca init/main.c:887 do_init_module+0x204/0x5f6 kernel/module.c:3460 load_module+0x66b2/0x8570 kernel/module.c:3808 __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 2806: set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x130/0x180 mm/kasan/common.c:458 slab_free_hook mm/slub.c:1409 [inline] slab_free_freelist_hook mm/slub.c:1436 [inline] slab_free mm/slub.c:2986 [inline] kmem_cache_free+0xa6/0x2a0 mm/slub.c:3002 pde_put+0x6e/0x80 fs/proc/generic.c:647 remove_proc_entry+0x1d3/0x420 fs/proc/generic.c:684 0xffffffffc10c031c 0xffffffffc10c0166 do_one_initcall+0xfa/0x5ca init/main.c:887 do_init_module+0x204/0x5f6 kernel/module.c:3460 load_module+0x66b2/0x8570 kernel/module.c:3808 __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8881f41fe500 which belongs to the cache proc_dir_entry of size 256 The buggy address is located 176 bytes inside of 256-byte region [ffff8881f41fe500, ffff8881f41fe600) The buggy address belongs to the page: page:ffffea0007d07f80 count:1 mapcount:0 mapping:ffff8881f6e69a00 index:0x0 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 dead000000000100 dead000000000200 ffff8881f6e69a00 raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881f41fe480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8881f41fe500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881f41fe580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881f41fe600: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8881f41fe680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb It should check the return value of atalk_proc_init fails, otherwise atalk_exit will trgger use-after-free in pde_subdir_find while unload the module.This patch fix error cleanup path of atalk_init Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/atalk.h2
-rw-r--r--net/appletalk/atalk_proc.c2
-rw-r--r--net/appletalk/ddp.c37
-rw-r--r--net/appletalk/sysctl_net_atalk.c5
4 files changed, 37 insertions, 9 deletions
diff --git a/include/linux/atalk.h b/include/linux/atalk.h
index 23f805562f4e..5a90f28d5ff2 100644
--- a/include/linux/atalk.h
+++ b/include/linux/atalk.h
@@ -158,7 +158,7 @@ extern int sysctl_aarp_retransmit_limit;
extern int sysctl_aarp_resolve_time;
#ifdef CONFIG_SYSCTL
-extern void atalk_register_sysctl(void);
+extern int atalk_register_sysctl(void);
extern void atalk_unregister_sysctl(void);
#else
#define atalk_register_sysctl() do { } while(0)
diff --git a/net/appletalk/atalk_proc.c b/net/appletalk/atalk_proc.c
index bd8734ef80b8..77f203f1febc 100644
--- a/net/appletalk/atalk_proc.c
+++ b/net/appletalk/atalk_proc.c
@@ -237,7 +237,7 @@ out:
return -ENOMEM;
}
-void __exit atalk_proc_exit(void)
+void atalk_proc_exit(void)
{
remove_proc_subtree("atalk", init_net.proc_net);
}
diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c
index 9b6bc5abe946..795fbc6c06aa 100644
--- a/net/appletalk/ddp.c
+++ b/net/appletalk/ddp.c
@@ -1910,12 +1910,16 @@ static const char atalk_err_snap[] __initconst =
/* Called by proto.c on kernel start up */
static int __init atalk_init(void)
{
- int rc = proto_register(&ddp_proto, 0);
+ int rc;
- if (rc != 0)
+ rc = proto_register(&ddp_proto, 0);
+ if (rc)
goto out;
- (void)sock_register(&atalk_family_ops);
+ rc = sock_register(&atalk_family_ops);
+ if (rc)
+ goto out_proto;
+
ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
if (!ddp_dl)
printk(atalk_err_snap);
@@ -1923,12 +1927,33 @@ static int __init atalk_init(void)
dev_add_pack(&ltalk_packet_type);
dev_add_pack(&ppptalk_packet_type);
- register_netdevice_notifier(&ddp_notifier);
+ rc = register_netdevice_notifier(&ddp_notifier);
+ if (rc)
+ goto out_sock;
+
aarp_proto_init();
- atalk_proc_init();
- atalk_register_sysctl();
+ rc = atalk_proc_init();
+ if (rc)
+ goto out_aarp;
+
+ rc = atalk_register_sysctl();
+ if (rc)
+ goto out_proc;
out:
return rc;
+out_proc:
+ atalk_proc_exit();
+out_aarp:
+ aarp_cleanup_module();
+ unregister_netdevice_notifier(&ddp_notifier);
+out_sock:
+ dev_remove_pack(&ppptalk_packet_type);
+ dev_remove_pack(&ltalk_packet_type);
+ unregister_snap_client(ddp_dl);
+ sock_unregister(PF_APPLETALK);
+out_proto:
+ proto_unregister(&ddp_proto);
+ goto out;
}
module_init(atalk_init);
diff --git a/net/appletalk/sysctl_net_atalk.c b/net/appletalk/sysctl_net_atalk.c
index c744a853fa5f..d945b7c0176d 100644
--- a/net/appletalk/sysctl_net_atalk.c
+++ b/net/appletalk/sysctl_net_atalk.c
@@ -45,9 +45,12 @@ static struct ctl_table atalk_table[] = {
static struct ctl_table_header *atalk_table_header;
-void atalk_register_sysctl(void)
+int __init atalk_register_sysctl(void)
{
atalk_table_header = register_net_sysctl(&init_net, "net/appletalk", atalk_table);
+ if (!atalk_table_header)
+ return -ENOMEM;
+ return 0;
}
void atalk_unregister_sysctl(void)