> From: syzbot > [mailto:syzbot+223310b454ba6b75974e@xxxxxxxxxxxxxxxxxxxxxxxxx] > Sent: Thursday, June 4, 2020 4:23 PM > Hello, > > syzbot found the following crash on: > > HEAD commit: e7b08814 Add linux-next specific files for 20200529 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=12d7b391100000 > kernel config: > https://syzkaller.appspot.com/x/.config?x=1e62421a5de6da96 > dashboard link: > https://syzkaller.appspot.com/bug?extid=223310b454ba6b75974e > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=108575d2100000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13291661100000 > > The bug was bisected to: > > commit aa724fe18a8a8285d0071c3bfc932efb090d142d > Author: Roberto Sassu <roberto.sassu@xxxxxxxxxx> > Date: Wed Mar 25 10:47:09 2020 +0000 > > ima: Switch to dynamically allocated buffer for template digests I think I found the issue. digests = kcalloc(NR_BANKS(ima_tpm_chip) + ima_extra_slots, sizeof(*digests), GFP_NOFS); if (!digests) { result = -ENOMEM; goto out; } (*entry)->digests = digests; (*entry)->template_desc = template_desc; [...] out: ima_free_template_entry(*entry); If digest is NULL we are going to ima_free_template_entry() without initializing (*entry)->template_desc. But we are using it in ima_free_template_entry(): void ima_free_template_entry(struct ima_template_entry *entry) { int i; for (i = 0; i < entry->template_desc->num_fields; i++) kfree(entry->template_data[i].data); Will send a patch shortly. Roberto HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063 Managing Director: Li Peng, Li Jian, Shi Yanli > bisection log: > https://syzkaller.appspot.com/x/bisect.txt?x=1616e896100000 > final crash: https://syzkaller.appspot.com/x/report.txt?x=1516e896100000 > console output: https://syzkaller.appspot.com/x/log.txt?x=1116e896100000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+223310b454ba6b75974e@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: aa724fe18a8a ("ima: Switch to dynamically allocated buffer for > template digests") > > RBP: 000000000000dcd4 R08: 0000000000000002 R09: 00000000004002c8 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402160 > R13: 00000000004021f0 R14: 0000000000000000 R15: 0000000000000000 > general protection fault, probably for non-canonical address > 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN > KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] > CPU: 0 PID: 6811 Comm: syz-executor925 Not tainted 5.7.0-rc7-next- > 20200529-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, > BIOS Google 01/01/2011 > RIP: 0010:ima_free_template_entry+0x4a/0x170 > security/integrity/ima/ima_api.c:27 > Code: fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 25 01 00 00 48 b8 00 00 00 00 00 fc ff > df 48 8b 5d 10 48 8d 7b 20 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 > 0f 8e d1 00 00 00 8b 5b 20 31 ff 89 > RSP: 0018:ffffc900018e7598 EFLAGS: 00010202 > RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff9200031cece > RDX: 0000000000000004 RSI: ffffffff836d8716 RDI: 0000000000000020 > RBP: ffff88809a078d80 R08: 0000000000000000 R09: ffffed1015cc719c > R10: ffff8880ae638cdb R11: ffffed1015cc719b R12: ffffc900018e7670 > R13: ffffffff8a06d650 R14: ffff88809a078d90 R15: 00000000fffffff4 > FS: 0000000000bc7880(0000) GS:ffff8880ae600000(0000) > knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000000 CR3: 00000000a6570000 CR4: 00000000001406f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > ima_alloc_init_template+0x3de/0x570 security/integrity/ima/ima_api.c:80 > ima_add_violation+0x109/0x1e0 security/integrity/ima/ima_api.c:148 > ima_rdwr_violation_check security/integrity/ima/ima_main.c:140 [inline] > process_measurement+0x1144/0x1750 > security/integrity/ima/ima_main.c:237 > ima_file_check+0xb9/0x100 security/integrity/ima/ima_main.c:491 > do_open fs/namei.c:3236 [inline] > path_openat+0x17a4/0x27d0 fs/namei.c:3351 > do_filp_open+0x192/0x260 fs/namei.c:3378 > do_sys_openat2+0x585/0x7a0 fs/open.c:1173 > do_sys_open+0xc3/0x140 fs/open.c:1189 > do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x441219 > Code: e8 5c ae 02 00 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 bb 0a > fc ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007ffca22cc218 EFLAGS: 00000246 ORIG_RAX: > 0000000000000002 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441219 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180 > RBP: 000000000000dcd4 R08: 0000000000000002 R09: 00000000004002c8 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402160 > R13: 00000000004021f0 R14: 0000000000000000 R15: 0000000000000000 > Modules linked in: > ---[ end trace d5e7ae4ed8ee55df ]--- > RIP: 0010:ima_free_template_entry+0x4a/0x170 > security/integrity/ima/ima_api.c:27 > Code: fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 25 01 00 00 48 b8 00 00 00 00 00 fc ff > df 48 8b 5d 10 48 8d 7b 20 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 > 0f 8e d1 00 00 00 8b 5b 20 31 ff 89 > RSP: 0018:ffffc900018e7598 EFLAGS: 00010202 > RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff9200031cece > RDX: 0000000000000004 RSI: ffffffff836d8716 RDI: 0000000000000020 > RBP: ffff88809a078d80 R08: 0000000000000000 R09: ffffed1015cc719c > R10: ffff8880ae638cdb R11: ffffed1015cc719b R12: ffffc900018e7670 > R13: ffffffff8a06d650 R14: ffff88809a078d90 R15: 00000000fffffff4 > FS: 0000000000bc7880(0000) GS:ffff8880ae600000(0000) > knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f1d9c03f078 CR3: 00000000a6570000 CR4: 00000000001406f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > For information about bisection process see: > https://goo.gl/tpsmEJ#bisection > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches
