Hi Ian, Miklos, I've just rebased KMSAN to v5.15-rc2 and am seeing the following reports at kernel boot-time: ===================================================== BUG: KMSAN: uninit-value in kernfs_dop_revalidate+0x61f/0x840 fs/kernfs/dir.c:1053 kernfs_dop_revalidate+0x61f/0x840 fs/kernfs/dir.c:1053 d_revalidate fs/namei.c:854 lookup_dcache fs/namei.c:1522 __lookup_hash+0x3a6/0x590 fs/namei.c:1543 filename_create+0x312/0x7c0 fs/namei.c:3657 do_mkdirat+0x103/0x930 fs/namei.c:3900 __do_sys_mkdir fs/namei.c:3931 __se_sys_mkdir fs/namei.c:3929 __x64_sys_mkdir+0xda/0x120 fs/namei.c:3929 do_syscall_x64 arch/x86/entry/common.c:51 Uninit was created at: slab_alloc_node mm/slub.c:3221 slab_alloc mm/slub.c:3230 kmem_cache_alloc+0x71f/0x1010 mm/slub.c:3235 __d_alloc+0x85/0xc60 fs/dcache.c:1744 d_alloc fs/dcache.c:1823 d_alloc_parallel+0x12b/0x2210 fs/dcache.c:2575 __lookup_slow+0x1a8/0x7e0 fs/namei.c:1642 lookup_slow+0xe0/0x140 fs/namei.c:1674 walk_component fs/namei.c:1970 link_path_walk+0x1252/0x18a0 fs/namei.c:2297 path_openat+0x395/0x5d30 fs/namei.c:3557 do_filp_open+0x29b/0x6a0 fs/namei.c:3588 do_sys_openat2+0x261/0x8f0 fs/open.c:1200 do_sys_open fs/open.c:1216 __do_sys_open fs/open.c:1224 __se_sys_open fs/open.c:1220 __x64_sys_open+0x308/0x370 fs/open.c:1220 do_syscall_x64 arch/x86/entry/common.c:51 ===================================================== Looks like some code forgets to initialize dentry->d_time before comparing it to parent->dir.rev in kernfs_dir_changed(). When I change __d_alloc() to allocate dentry with __GFP_ZERO, the problem goes away. Could you please take a look? Thanks, Alex -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg
