In the Linux kernel, the following vulnerability has been resolved:
ext4: dax: fix overflowing extents beyond inode size when partially writing
The dax_iomap_rw() does two things in each iteration: map written blocks
and copy user data to blocks. If the process is killed by user(See signal
handling in dax_iomap_iter()), the copied data will be returned and added
on inode size, which means that the length of written extents may exceed
the inode size, then fsck will fail. An example is given as:
dd if=/dev/urandom of=file bs=4M count=1
dax_iomap_rw
iomap_iter // round 1
ext4_iomap_begin
ext4_iomap_alloc // allocate 0~2M extents(written flag)
dax_iomap_iter // copy 2M data
iomap_iter // round 2
iomap_iter_advance
iter->pos += iter->processed // iter->pos = 2M
ext4_iomap_begin
ext4_iomap_alloc // allocate 2~4M extents(written flag)
dax_iomap_iter
fatal_signal_pending
done = iter->pos - iocb->ki_pos // done = 2M
ext4_handle_inode_extension
ext4_update_inode_size // inode size = 2M
fsck reports: Inode 13, i_size is 2097152, should be 4194304. Fix?
Fix the problem by truncating extents if the written length is smaller
than expected.
Metrics
Affected Vendors & Products
References
History
Fri, 22 Nov 2024 15:45:00 +0000
Type | Values Removed | Values Added |
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Weaknesses | CWE-1214 |
Mon, 28 Oct 2024 17:30:00 +0000
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First Time appeared |
Linux
Linux linux Kernel |
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Weaknesses | NVD-CWE-noinfo | |
CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
Vendors & Products |
Linux
Linux linux Kernel |
Wed, 23 Oct 2024 01:30:00 +0000
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References |
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Metrics |
threat_severity
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cvssV3_1
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Tue, 22 Oct 2024 14:15:00 +0000
Type | Values Removed | Values Added |
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Metrics |
ssvc
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Mon, 21 Oct 2024 19:00:00 +0000
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Description | In the Linux kernel, the following vulnerability has been resolved: ext4: dax: fix overflowing extents beyond inode size when partially writing The dax_iomap_rw() does two things in each iteration: map written blocks and copy user data to blocks. If the process is killed by user(See signal handling in dax_iomap_iter()), the copied data will be returned and added on inode size, which means that the length of written extents may exceed the inode size, then fsck will fail. An example is given as: dd if=/dev/urandom of=file bs=4M count=1 dax_iomap_rw iomap_iter // round 1 ext4_iomap_begin ext4_iomap_alloc // allocate 0~2M extents(written flag) dax_iomap_iter // copy 2M data iomap_iter // round 2 iomap_iter_advance iter->pos += iter->processed // iter->pos = 2M ext4_iomap_begin ext4_iomap_alloc // allocate 2~4M extents(written flag) dax_iomap_iter fatal_signal_pending done = iter->pos - iocb->ki_pos // done = 2M ext4_handle_inode_extension ext4_update_inode_size // inode size = 2M fsck reports: Inode 13, i_size is 2097152, should be 4194304. Fix? Fix the problem by truncating extents if the written length is smaller than expected. | |
Title | ext4: dax: fix overflowing extents beyond inode size when partially writing | |
References |
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MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-10-21T18:54:06.465Z
Updated: 2024-12-19T09:31:19.991Z
Reserved: 2024-10-21T12:17:06.062Z
Link: CVE-2024-50015
Vulnrichment
Updated: 2024-10-22T13:28:11.693Z
NVD
Status : Analyzed
Published: 2024-10-21T19:15:04.890
Modified: 2024-10-28T17:13:53.143
Link: CVE-2024-50015
Redhat