https://bugzilla.kernel.org/show_bug.cgi?id=199635 Bug ID: 199635 Summary: UBSAN: Undefined behaviour in fs/ext4/readpage.c Product: File System Version: 2.5 Kernel Version: 4.16.7 Hardware: x86-64 OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: ext4 Assignee: fs_ext4@xxxxxxxxxxxxxxxxxxxx Reporter: combuster@xxxxxxxxxxxx Regression: No After recompiling the 4.16.7 kernel with gcc 8.1, UBSAN reports the following: [ 25.134709] EXT4-fs (dm-0): mounted filesystem with ordered data mode. Opts: (null) [ 25.171336] ================================================================================ [ 25.173900] UBSAN: Undefined behaviour in fs/ext4/readpage.c:129:13 [ 25.176412] member access within null pointer of type 'struct page' [ 25.178890] CPU: 1 PID: 1 Comm: switch_root Not tainted 4.16.7-CUSTOM #1 [ 25.180655] Hardware name: Gigabyte Technology Co., Ltd. H67MA-UD2H-B3/H67MA-UD2H-B3, BIOS F8 03/27/2012 [ 25.182334] Call Trace: [ 25.183982] dump_stack+0x62/0x9f [ 25.185643] ubsan_epilogue+0x9/0x35 [ 25.187254] handle_null_ptr_deref+0x80/0x90 [ 25.188855] __ubsan_handle_type_mismatch_v1+0x6a/0x80 [ 25.190457] ext4_mpage_readpages+0x10f5/0x1120 [ext4] [ 25.192067] ? __alloc_pages_nodemask+0x1cb/0x1630 [ 25.193640] ? __do_page_cache_readahead+0x30d/0x5a0 [ 25.195181] ? ondemand_readahead+0x24e/0x440 [ 25.196675] ? ondemand_readahead+0x24e/0x440 [ 25.198504] ? generic_file_buffered_read+0x7b1/0x10f0 [ 25.200580] ? find_held_lock+0x3d/0x140 [ 25.202656] ? __vfs_read+0x200/0x330 [ 25.204736] ? vfs_read+0x9c/0x1a0 [ 25.206797] ? kernel_read+0x67/0x140 [ 25.208830] ? prepare_binprm+0x1d8/0x350 [ 25.210857] ? do_execveat_common+0x664/0xe50 [ 25.212861] ? SyS_execve+0x23/0x30 [ 25.214879] ? do_syscall_64+0xad/0x5cc [ 25.216882] ? page_fault+0x2f/0x50 [ 25.218859] ? entry_SYSCALL_64_after_hwframe+0x3d/0xa2 [ 25.220826] ================================================================================ UBSAN reported nothing when the same kernel was compiled with gcc 7.3.1 from Arch Linux repositories. -- You are receiving this mail because: You are watching the assignee of the bug.
