memory leak in policydb_read

From: syzbot
Date: Tue Jul 23 2019 - 05:18:08 EST


syzbot found the following crash on:

HEAD commit: c6dd78fc Merge branch 'x86-urgent-for-linus' of git://git...
git tree: upstream
console output:
kernel config:
dashboard link:
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:
C reproducer:

The bug was bisected to:

commit d9570ee3bd1d4f20ce63485f5ef05663866fe6c0
Author: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Date: Sat Jan 13 00:53:10 2018 +0000

kmemleak: allow to coexist with fault injection

bisection log:
final crash:
console output:

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+fee3a14d4cdf92646287@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: d9570ee3bd1d ("kmemleak: allow to coexist with fault injection")

BUG: memory leak
unreferenced object 0xffff888123547c80 (size 64):
comm "syz-executor647", pid 6976, jiffies 4294940919 (age 7.920s)
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[<0000000019b1b22a>] kmemleak_alloc_recursive /./include/linux/kmemleak.h:43 [inline]
[<0000000019b1b22a>] slab_post_alloc_hook /mm/slab.h:522 [inline]
[<0000000019b1b22a>] slab_alloc /mm/slab.c:3319 [inline]
[<0000000019b1b22a>] kmem_cache_alloc_trace+0x145/0x280 /mm/slab.c:3548
[<00000000d64c33c7>] kmalloc /./include/linux/slab.h:552 [inline]
[<00000000d64c33c7>] kzalloc /./include/linux/slab.h:748 [inline]
[<00000000d64c33c7>] roles_init /security/selinux/ss/policydb.c:188 [inline]
[<00000000d64c33c7>] policydb_init /security/selinux/ss/policydb.c:294 [inline]
[<00000000d64c33c7>] policydb_read+0x141/0x1b80 /security/selinux/ss/policydb.c:2259
[<000000004dd18ef6>] security_load_policy+0x182/0x740 /security/selinux/ss/services.c:2141
[<000000004f5bb277>] sel_write_load+0x101/0x1f0 /security/selinux/selinuxfs.c:564
[<00000000ee05c840>] __vfs_write+0x43/0xa0 /fs/read_write.c:494
[<000000008ca23315>] vfs_write /fs/read_write.c:558 [inline]
[<000000008ca23315>] vfs_write+0xee/0x210 /fs/read_write.c:542
[<00000000d97bcbc9>] ksys_write+0x7c/0x130 /fs/read_write.c:611
[<000000007a3f006b>] __do_sys_write /fs/read_write.c:623 [inline]
[<000000007a3f006b>] __se_sys_write /fs/read_write.c:620 [inline]
[<000000007a3f006b>] __x64_sys_write+0x1e/0x30 /fs/read_write.c:620
[<000000001c16ef20>] do_syscall_64+0x76/0x1a0 /arch/x86/entry/common.c:296
[<000000007784189d>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

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