loop4: detected capacity change from 0 to 1024
=====================================================
BUG: KMSAN: uninit-value in __hfsplus_ext_read_extent fs/hfsplus/extents.c:167 [inline]
BUG: KMSAN: uninit-value in __hfsplus_ext_cache_extent+0x7cb/0x990 fs/hfsplus/extents.c:191
 __hfsplus_ext_read_extent fs/hfsplus/extents.c:167 [inline]
 __hfsplus_ext_cache_extent+0x7cb/0x990 fs/hfsplus/extents.c:191
 hfsplus_ext_read_extent fs/hfsplus/extents.c:218 [inline]
 hfsplus_file_extend+0x7b5/0x1df0 fs/hfsplus/extents.c:462
 hfsplus_get_block+0xfc3/0x1a20 fs/hfsplus/extents.c:245
 __block_write_begin_int+0xaab/0x3000 fs/buffer.c:2116
 block_write_begin fs/buffer.c:2227 [inline]
 cont_write_begin+0x10df/0x1ba0 fs/buffer.c:2566
 hfsplus_write_begin+0x85/0x130 fs/hfsplus/inode.c:46
 generic_perform_write+0x3f4/0x10c0 mm/filemap.c:4103
 __generic_file_write_iter+0x213/0x460 mm/filemap.c:4220
 generic_file_write_iter+0x131/0x980 mm/filemap.c:4246
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0xb31/0x1560 fs/read_write.c:684
 ksys_write fs/read_write.c:736 [inline]
 __do_sys_write fs/read_write.c:747 [inline]
 __se_sys_write fs/read_write.c:744 [inline]
 __x64_sys_write+0x1fb/0x4d0 fs/read_write.c:744
 x64_sys_call+0x38c3/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x1b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 __alloc_frozen_pages_noprof+0x689/0xf00 mm/page_alloc.c:4993
 alloc_pages_mpol+0x328/0x860 mm/mempolicy.c:2301
 alloc_frozen_pages_noprof+0xf7/0x200 mm/mempolicy.c:2372
 alloc_slab_page mm/slub.c:2468 [inline]
 allocate_slab+0x24d/0x1210 mm/slub.c:2632
 new_slab mm/slub.c:2686 [inline]
 ___slab_alloc+0xfec/0x3480 mm/slub.c:3872
 __slab_alloc mm/slub.c:3962 [inline]
 __slab_alloc_node mm/slub.c:4037 [inline]
 slab_alloc_node mm/slub.c:4198 [inline]
 __kmalloc_cache_noprof+0x8ff/0xed0 mm/slub.c:4367
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 ref_tracker_alloc+0x13a/0x7a0 lib/ref_tracker.c:203
 __netdev_tracker_alloc include/linux/netdevice.h:4331 [inline]
 netdev_tracker_alloc include/linux/netdevice.h:4343 [inline]
 netdev_get_by_index+0xf6/0x1b0 net/core/dev.c:1006
 fib6_nh_init+0x172/0x3400 net/ipv6/route.c:3583
 ip6_route_info_create+0x1099/0x1ee0 net/ipv6/route.c:3852
 ip6_route_add+0x48/0x370 net/ipv6/route.c:3896
 addrconf_prefix_route net/ipv6/addrconf.c:2487 [inline]
 inet6_addr_add+0xb6a/0x1330 net/ipv6/addrconf.c:3052
 inet6_rtm_newaddr+0x1743/0x1ad0 net/ipv6/addrconf.c:5060
 rtnetlink_rcv_msg+0x106c/0x14b0 net/core/rtnetlink.c:6955
 netlink_rcv_skb+0x54a/0x680 net/netlink/af_netlink.c:2534
 rtnetlink_rcv+0x35/0x40 net/core/rtnetlink.c:6982
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0xed5/0x1290 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x10b3/0x1250 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x330/0x3d0 net/socket.c:727
 __sys_sendto+0x590/0x710 net/socket.c:2180
 __do_sys_sendto net/socket.c:2187 [inline]
 __se_sys_sendto net/socket.c:2183 [inline]
 __x64_sys_sendto+0x130/0x200 net/socket.c:2183
 x64_sys_call+0x3c0b/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x1b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 8604 Comm: syz.4.373 Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 PREEMPT(undef) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
=====================================================