[syzbot] [fs?] general protection fault in path_put

[syzbot] [fs?] general protection fault in path_put

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    11028ab62899 Merge tag 'probes-fixes-v7.2-rc5' of git://gi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=179d4aea580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=145fa60d73086782
dashboard link: https://syzkaller.appspot.com/bug?extid=1686d17ae576cc5f8a57
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14e497b1580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14e2a48e580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-11028ab6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e2be78614a29/vmlinux-11028ab6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/301a11d315af/bzImage-11028ab6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1686d17ae576cc5f8a57@syzkaller.appspotmail.com

RBP: 00007fffaa9085c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007feae0225fac R14: 00007feae0225fa0 R15: 00007feae0225fa0
 </TASK>
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047]
CPU: 0 UID: 0 PID: 5912 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:path_put+0x22/0x70 fs/namei.c:722
Code: 90 90 90 90 90 90 90 90 f3 0f 1e fa 53 48 89 fb e8 a3 61 78 ff 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 29 48 8b 7b 08 e8 4f 97 04 00 48 89 da 48 b8 00 00
RSP: 0018:ffffc900040c7a68 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: 000000000000003c RCX: 0000000000000000
RDX: 0000000000000008 RSI: ffffffff8291fe9d RDI: 0000000000000044
RBP: ffffc900040c7bf8 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff9b74bc40 R11: 0000000000000000 R12: ffff888022ab1f88
R13: ffff88802dcb4a60 R14: ffff888022a9c680 R15: fffffffffffffff4
FS:  000055557d29f500(0000) GS:ffff8880d5ddc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32f63fff CR3: 000000003cf56000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 free_trace_uprobe kernel/trace/trace_uprobe.c:374 [inline]
 free_trace_uprobe kernel/trace/trace_uprobe.c:369 [inline]
 __free_free_trace_uprobe kernel/trace/trace_uprobe.c:536 [inline]
 __trace_uprobe_create+0x96d/0x22f0 kernel/trace/trace_uprobe.c:545
 trace_probe_create+0xef/0x100 kernel/trace/trace_probe.c:2371
 dyn_event_create+0x46/0x70 kernel/trace/trace_dynevent.c:128
 create_or_delete_trace_uprobe+0x5a/0xb0 kernel/trace/trace_uprobe.c:739
 trace_parse_run_command+0x1ab/0x3b0 kernel/trace/trace.c:9565
 vfs_write+0x2aa/0x1050 fs/read_write.c:685
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feadff9df99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffaa908558 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007feae0225fa0 RCX: 00007feadff9df99
RDX: 000000000000000f RSI: 0000200000000180 RDI: 0000000000000004
RBP: 00007fffaa9085c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007feae0225fac R14: 00007feae0225fa0 R15: 00007feae0225fa0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:path_put+0x22/0x70 fs/namei.c:722
Code: 90 90 90 90 90 90 90 90 f3 0f 1e fa 53 48 89 fb e8 a3 61 78 ff 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 29 48 8b 7b 08 e8 4f 97 04 00 48 89 da 48 b8 00 00
RSP: 0018:ffffc900040c7a68 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: 000000000000003c RCX: 0000000000000000
RDX: 0000000000000008 RSI: ffffffff8291fe9d RDI: 0000000000000044
RBP: ffffc900040c7bf8 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff9b74bc40 R11: 0000000000000000 R12: ffff888022ab1f88
R13: ffff88802dcb4a60 R14: ffff888022a9c680 R15: fffffffffffffff4
FS:  000055557d29f500(0000) GS:ffff8880d5edc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32f24008 CR3: 000000003cf56000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	90                   	nop
   1:	90                   	nop
   2:	90                   	nop
   3:	90                   	nop
   4:	90                   	nop
   5:	90                   	nop
   6:	90                   	nop
   7:	90                   	nop
   8:	f3 0f 1e fa          	endbr64
   c:	53                   	push   %rbx
   d:	48 89 fb             	mov    %rdi,%rbx
  10:	e8 a3 61 78 ff       	call   0xff7861b8
  15:	48 8d 7b 08          	lea    0x8(%rbx),%rdi
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	75 29                	jne    0x59
  30:	48 8b 7b 08          	mov    0x8(%rbx),%rdi
  34:	e8 4f 97 04 00       	call   0x49788
  39:	48 89 da             	mov    %rbx,%rdx
  3c:	48                   	rex.W
  3d:	b8                   	.byte 0xb8


---
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Forwarded: [PATCH] tracing: uprobes: Fix invalid free on failed alloc_trace_uprobe

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [PATCH] tracing: uprobes: Fix invalid free on failed alloc_trace_uprobe
Author: ryan.mehri1@gmail.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 11028ab62899

Signed-off-by: Ryan Mehri <ryan.mehri1@gmail.com>
---
 kernel/trace/trace_uprobe.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index c274346853d1..c9ec9283d1ab 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -688,6 +688,7 @@ static int __trace_uprobe_create(int argc, const char **argv)
 	tu = alloc_trace_uprobe(group, event, argc, is_return);
 	if (IS_ERR(tu)) {
 		ret = PTR_ERR(tu);
+		tu = NULL;
 		/* This must return -ENOMEM otherwise there is a bug */
 		WARN_ON_ONCE(ret != -ENOMEM);
 		return ret;
-- 
2.55.0

Re: [syzbot] [fs?] general protection fault in path_put

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+1686d17ae576cc5f8a57@syzkaller.appspotmail.com
Tested-by: syzbot+1686d17ae576cc5f8a57@syzkaller.appspotmail.com

Tested on:

commit:         11028ab6 Merge tag 'probes-fixes-v7.2-rc5' of git://gi..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=14930cc6580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=145fa60d73086782
dashboard link: https://syzkaller.appspot.com/bug?extid=1686d17ae576cc5f8a57
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15029db9580000

Note: testing is done by a robot and is best-effort only.