Bug 2373510 (CVE-2022-50082)

Summary: CVE-2022-50082 kernel: ext4: fix warning in ext4_iomap_begin as race between bmap and write
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-06-18 12:06:11 UTC
In the Linux kernel, the following vulnerability has been resolved:

ext4: fix warning in ext4_iomap_begin as race between bmap and write

We got issue as follows:
------------[ cut here ]------------
WARNING: CPU: 3 PID: 9310 at fs/ext4/inode.c:3441 ext4_iomap_begin+0x182/0x5d0
RIP: 0010:ext4_iomap_begin+0x182/0x5d0
RSP: 0018:ffff88812460fa08 EFLAGS: 00010293
RAX: ffff88811f168000 RBX: 0000000000000000 RCX: ffffffff97793c12
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: ffff88812c669160 R08: ffff88811f168000 R09: ffffed10258cd20f
R10: ffff88812c669077 R11: ffffed10258cd20e R12: 0000000000000001
R13: 00000000000000a4 R14: 000000000000000c R15: ffff88812c6691ee
FS:  00007fd0d6ff3740(0000) GS:ffff8883af180000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd0d6dda290 CR3: 0000000104a62000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 iomap_apply+0x119/0x570
 iomap_bmap+0x124/0x150
 ext4_bmap+0x14f/0x250
 bmap+0x55/0x80
 do_vfs_ioctl+0x952/0xbd0
 __x64_sys_ioctl+0xc6/0x170
 do_syscall_64+0x33/0x40
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Above issue may happen as follows:
          bmap                    write
bmap
  ext4_bmap
    iomap_bmap
      ext4_iomap_begin
                            ext4_file_write_iter
			      ext4_buffered_write_iter
			        generic_perform_write
				  ext4_da_write_begin
				    ext4_da_write_inline_data_begin
				      ext4_prepare_inline_data
				        ext4_create_inline_data
					  ext4_set_inode_flag(inode,
						EXT4_INODE_INLINE_DATA);
      if (WARN_ON_ONCE(ext4_has_inline_data(inode))) ->trigger bug_on

To solved above issue hold inode lock in ext4_bamp.

Comment 1 Avinash Hanwate 2025-06-19 20:15:47 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025061857-CVE-2022-50082-f427@gregkh/T