{"id":"AZL-42118","summary":"CVE-2024-35849 affecting package hyperv-daemons for versions less than 6.6.35.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix information leak in btrfs_ioctl_logical_to_ino()\n\nSyzbot reported the following information leak for in\nbtrfs_ioctl_logical_to_ino():\n\n  BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]\n  BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x110 lib/usercopy.c:40\n   instrument_copy_to_user include/linux/instrumented.h:114 [inline]\n   _copy_to_user+0xbc/0x110 lib/usercopy.c:40\n   copy_to_user include/linux/uaccess.h:191 [inline]\n   btrfs_ioctl_logical_to_ino+0x440/0x750 fs/btrfs/ioctl.c:3499\n   btrfs_ioctl+0x714/0x1260\n   vfs_ioctl fs/ioctl.c:51 [inline]\n   __do_sys_ioctl fs/ioctl.c:904 [inline]\n   __se_sys_ioctl+0x261/0x450 fs/ioctl.c:890\n   __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890\n   x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17\n   do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n   do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n  Uninit was created at:\n   __kmalloc_large_node+0x231/0x370 mm/slub.c:3921\n   __do_kmalloc_node mm/slub.c:3954 [inline]\n   __kmalloc_node+0xb07/0x1060 mm/slub.c:3973\n   kmalloc_node include/linux/slab.h:648 [inline]\n   kvmalloc_node+0xc0/0x2d0 mm/util.c:634\n   kvmalloc include/linux/slab.h:766 [inline]\n   init_data_container+0x49/0x1e0 fs/btrfs/backref.c:2779\n   btrfs_ioctl_logical_to_ino+0x17c/0x750 fs/btrfs/ioctl.c:3480\n   btrfs_ioctl+0x714/0x1260\n   vfs_ioctl fs/ioctl.c:51 [inline]\n   __do_sys_ioctl fs/ioctl.c:904 [inline]\n   __se_sys_ioctl+0x261/0x450 fs/ioctl.c:890\n   __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890\n   x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17\n   do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n   do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n  Bytes 40-65535 of 65536 are uninitialized\n  Memory access of size 65536 starts at ffff888045a40000\n\nThis happens, because we're copying a 'struct btrfs_data_container' back\nto user-space. This btrfs_data_container is allocated in\n'init_data_container()' via kvmalloc(), which does not zero-fill the\nmemory.\n\nFix this by using kvzalloc() which zeroes out the memory on allocation.","modified":"2026-04-01T05:14:29.549919Z","published":"2024-05-17T15:15:21Z","upstream":["CVE-2024-35849"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-35849"}],"affected":[{"package":{"name":"hyperv-daemons","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/hyperv-daemons"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.35.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-42118.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H"}]}