On Mon, Sep 09, 2024 at 01:53:24PM GMT, Chandan Babu R wrote: > Hi, > > linux-next/fs-next released on 6th September is failing to boot on a x86 > guest, > > [ 42.659136] Oops: general protection fault, probably for non-canonical address 0xdffffc000000000b: 0000 [#1] PREEMPT SMP KASAN NOPTI > [ 42.660501] fbcon: Taking over console > [ 42.660930] KASAN: null-ptr-deref in range [0x0000000000000058-0x000000000000005f] > [ 42.661752] CPU: 1 UID: 0 PID: 1589 Comm: dtprobed Not tainted 6.11.0-rc6+ #1 > [ 42.662565] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.6.6 08/22/2023 > [ 42.663472] RIP: 0010:fuse_get_req+0x36b/0x990 [fuse] > [ 42.664046] Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 8c 05 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6d 08 48 8d 7d 58 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 4d 05 00 00 f6 45 59 20 0f 85 06 03 00 00 48 83 > [ 42.666945] RSP: 0018:ffffc900009a7730 EFLAGS: 00010212 > [ 42.668837] RAX: dffffc0000000000 RBX: 1ffff92000134eed RCX: ffffffffc20dec9a > [ 42.670122] RDX: 000000000000000b RSI: 0000000000000008 RDI: 0000000000000058 > [ 42.672154] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1022110172 > [ 42.672160] R10: ffff888110880b97 R11: ffffc900009a737a R12: 0000000000000001 > [ 42.672179] R13: ffff888110880b60 R14: ffff888110880b90 R15: ffff888169973840 > [ 42.672186] FS: 00007f28cd21d7c0(0000) GS:ffff8883ef280000(0000) knlGS:0000000000000000 > [ 42.672191] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 42.[ CR02: ;32m00007f3237366208 CR3: 0 OK 79e001 CR4: 0000000000770ef0 > [ 42.672214] PKRU: 55555554 > [ 42.672218] Call Trace: > [ 42.672223] <TASK> > [ 42.672226] ? die_addr+0x41/0xa0 > [ 42.672238] ? exc_general_protection+0x14c/0x230 > [ 42.672250] ? asm_exc_general_protection+0x26/0x30 > [ 42.672260] ? fuse_get_req+0x77a/0x990 [fuse] > [ 42.672281] ? fuse_get_req+0x36b/0x990 [fuse] > [ 42.672300] ? kasan_unpoison+0x27/0x60 > [ 42.672310] ? __pfx_fuse_get_req+0x10/0x10 [fuse] > [ 42.672327] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 42.672333] ? alloc_pages_mpol_noprof+0x195/0x440 > [ 42.672340] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 42.672345] ? kasan_unpoison+0x27/0x60 > [ 42.672350] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 42.672355] ? __kasan_slab_alloc+0x4d/0x90 > [ 42.672362] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 42.672367] ? __kmalloc_cache_noprof+0x134/0x350 > [ 42.672376] fuse_simple_background+0xe7/0x180 [fuse] I think this is basically: fuse_simple_background() -> !args->force -> fuse_get_req(NULL, fm, true); and there you have fm->sb->s_iflags & SB_I_NOIDMAP with idmap == NULL afaict. That's why I'm insistent passing NULL is a problem. If I'm not mistaken this should be fixed by Alex's patchset to not pass NULL. I'll go review that now.
