Messages in this thread | | | Subject | Re: WARNING: suspicious RCU usage with PROVE_RCU_LIST=y | From | John Johansen <> | Date | Thu, 14 May 2020 12:38:35 -0700 |
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On 5/14/20 11:24 AM, Amol Grover wrote: > On Mon, Apr 06, 2020 at 05:11:34PM +0530, Amol Grover wrote: >> Hello, >> >> With respect to the patch https://lore.kernel.org/patchwork/patch/1202512/ >> I boot tested with CONFIG_PROVE_RCU_LIST=y and encountered a susppicious RCU >> usage warning in "security/apparmor/include/lib.h". I thought of going forward >> and fix it myself, however, while going through the stack trace and the actual >> code, I found that the function (__lookupn_profile) is required to be called >> with rcu_read_locK() but the splat proves it otherwise. >> >> [ 12.727582] ============================= >> [ 12.727599] WARNING: suspicious RCU usage >> [ 12.727601] 5.5.4-stable #17 Tainted: G E >> [ 12.727602] ----------------------------- >> [ 12.727604] security/apparmor/include/lib.h:191 RCU-list traversed in non-reader section!! >> [ 12.727605] >> other info that might help us debug this: >> >> [ 12.727606] >> rcu_scheduler_active = 2, debug_locks = 1 >> [ 12.727608] 2 locks held by apparmor_parser/506: >> [ 12.727609] #0: ffff9f0687562490 (sb_writers#10){.+.+}, at: vfs_write+0x140/0x1a0 >> [ 12.727614] #1: ffff9f0687f09ca8 (&ns->lock){+.+.}, at: aa_replace_profiles+0x17a/0xdd0 >> [ 12.727619] >> stack backtrace: >> [ 12.727621] CPU: 3 PID: 506 Comm: apparmor_parser Tainted: G E 5.5.4-stable #17 >> [ 12.727622] Hardware name: Gigabyte Technology Co., Ltd. Z170-D3H/Z170-D3H-CF, BIOS F21 03/06/2017 >> [ 12.727623] Call Trace: >> [ 12.727627] dump_stack+0x8f/0xd0 >> [ 12.727630] __lookupn_profile+0x19c/0x1a0 >> [ 12.727632] ? aa_unpack+0x51b/0x580 >> [ 12.727636] __lookup_replace+0x34/0xc0 >> [ 12.727640] aa_replace_profiles+0x2a0/0xdd0 >> [ 12.727649] policy_update+0x106/0x370 >> [ 12.727653] profile_replace+0xa3/0x110 >> [ 12.727657] vfs_write+0xb9/0x1a0 >> [ 12.727661] ksys_write+0x68/0xe0 >> [ 12.727666] do_syscall_64+0x5c/0xe0 >> [ 12.727669] entry_SYSCALL_64_after_hwframe+0x49/0xbe >> [ 12.727671] RIP: 0033:0x7ff83fec7f93 >> [ 12.727673] Code: 75 05 48 83 c4 58 c3 e8 eb 41 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 55 c3 0f 1f 40 00 48 83 ec 28 48 89 54 24 18 >> [ 12.727674] RSP: 002b:00007ffcebb5c398 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 >> [ 12.727676] RAX: ffffffffffffffda RBX: 0000000000007131 RCX: 00007ff83fec7f93 >> [ 12.727677] RDX: 0000000000007131 RSI: 00005610fd804a40 RDI: 0000000000000006 >> [ 12.727678] RBP: 00005610fd804a40 R08: 0000000000007131 R09: 00005610fd802f38 >> [ 12.727680] R10: fffffffffffffa8a R11: 0000000000000246 R12: 0000000000000000 >> [ 12.727681] R13: 0000000000000006 R14: 00005610fd7dd490 R15: 0000000000007131 >> >> Thanks >> Amol > > Hello, > > Just a friendly request to please go through the above _bug_. > yep, thanks. I am looking into to it now.
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