Linux Kernel CVE-2022-50346

This vulnerability is classified as Use of Uninitialized Resource (CWE-908), which allows attackers to access uninitialized memory causing crashes or information disclosure. In the Linux kernel, the following vulnerability has been resolved: ext4: init quota for 'old.inode' in 'ext4_rename' Syzbot found the following issue: ext4_parse_param: s_want_extra_isize=128 ext4_inode_info_init: s_want_extra_isize=32 ext4_rename: old.inode=ffff88823869a2c8 old.dir=ffff888238699828 new.inode=ffff88823869d7e8 new.dir=ffff888238699828 __ext4_mark_inode_dirty: inode=ffff888238699828 ea_isize=32 want_ea_size=128 __ext4_mark_inode_dirty: inode=ffff88823869a2c8 ea_isize=32 want_ea_size=128 ext4_xattr_block_set: inode=ffff88823869a2c8 ------------[ cut here ]------------ WARNING: CPU: 13 PID: 2234 at fs/ext4/xattr.c:2070 ext4_xattr_block_set.cold+0x22/0x980 Modules linked in: RIP: 0010:ext4_xattr_block_set.cold+0x22/0x980 RSP: 0018:ffff888227d3f3b0 EFLAGS: 00010202 RAX: 0000000000000001 RBX: ffff88823007a000 RCX: 0000000000000000 RDX: 0000000000000a03 RSI: 0000000000000040 RDI: ffff888230078178 RBP: 0000000000000000 R08: 000000000000002c R09: ffffed1075c7df8e R10: ffff8883ae3efc6b R11: ffffed1075c7df8d R12: 0000000000000000 R13: ffff88823869a2c8 R14: ffff8881012e0460 R15: dffffc0000000000 FS: 00007f350ac1f740(0000) GS:ffff8883ae200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f350a6ed6a0 CR3: 0000000237456000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? ext4_xattr_set_entry+0x3b7/0x2320 ? ext4_xattr_block_set+0x0/0x2020 ? ext4_xattr_set_entry+0x0/0x2320 ? ext4_xattr_check_entries+0x77/0x310 ? ext4_xattr_ibody_set+0x23b/0x340 ext4_xattr_move_to_block+0x594/0x720 ext4_expand_extra_isize_ea+0x59a/0x10f0 __ext4_expand_extra_isize+0x278/0x3f0 __ext4_mark_inode_dirty.cold+0x347/0x410 ext4_rename+0xed3/0x174f vfs_rename+0x13a7/0x2510 do_renameat2+0x55d/0x920 __x64_sys_rename+0x7d/0xb0 do_syscall_64+0x3b/0xa0 entry_SYSCALL_64_after_hwframe+0x72/0xdc As 'ext4_rename' will modify 'old.inode' ctime and mark inode dirty, which may trigger expand 'extra_isize' and allocate block. If inode didn't init quota will lead to warning. To solve above issue, init 'old.inode' firstly in 'ext4_rename'. Affected products include: Linux Linux Kernel.