Re: UBSAN: shift-out-of-bounds in validate_sb_layout
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2024-05-20 14:31:16
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On Mon, 20 May 2024 15:02:26 +0800 "Ubisectech Sirius" [off-list ref] wrote:
Hello. We are Ubisectech Sirius Team, the vulnerability lab of China ValiantSec. Recently, our team has discovered a issue in Linux kernel 6.7. Attached to the email were a PoC file of the issue. Stack dump: UBSAN: shift-out-of-bounds in fs/bcachefs/super-io.c:310:18 shift exponent 127 is too large for 32-bit type 'int' CPU: 0 PID: 14408 Comm: syz-executor.3 Not tainted 6.7.0 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x136/0x150 lib/dump_stack.c:106 ubsan_epilogue lib/ubsan.c:217 [inline] __ubsan_handle_shift_out_of_bounds+0x24b/0x430 lib/ubsan.c:387 validate_sb_layout.cold+0x1a/0x51 fs/bcachefs/super-io.c:310 bch2_read_super+0x980/0x1000 fs/bcachefs/super-io.c:786 bch2_fs_open+0x471/0x3890 fs/bcachefs/super.c:1922 bch2_mount+0x538/0x13c0 fs/bcachefs/fs.c:1863 legacy_get_tree+0x109/0x220 fs/fs_context.c:662 vfs_get_tree+0x93/0x380 fs/super.c:1771 do_new_mount fs/namespace.c:3337 [inline] path_mount+0x679/0x1e40 fs/namespace.c:3664 do_mount fs/namespace.c:3677 [inline] __do_sys_mount fs/namespace.c:3886 [inline] __se_sys_mount fs/namespace.c:3863 [inline] __x64_sys_mount+0x287/0x310 fs/namespace.c:3863 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x43/0x120 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7f41e1091b3e Code: 48 c7 c0 ff ff ff ff eb aa e8 be 0d 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 f3 0f 1e fa 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f41e1d22e38 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000005d82 RCX: 00007f41e1091b3e RDX: 0000000020005d80 RSI: 0000000020000100 RDI: 00007f41e1d22e90 RBP: 00007f41e1d22ed0 R08: 00007f41e1d22ed0 R09: 0000000000000080 R10: 0000000000000080 R11: 0000000000000202 R12: 0000000020005d80 R13: 0000000020000100 R14: 00007f41e1d22e90 R15: 0000000020005e00 </TASK> Thank you for taking the time to read this email and we look forward to working with you further.
I'm not sure why this is getting Cc'd to linux-trace-kernel. That's for anything to do with the tracing code (trace events, tracepoints, kprobes, uprobes, function tracer etc). What part of tracing is this for? -- Steve