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CVE-2024-26956

nilfs2: fix failure to detect DAT corruption in btree and direct mappings PUBLISHED

Description (CNA)

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix failure to detect DAT corruption in btree and direct mappings Patch series "nilfs2: fix kernel bug at submit_bh_wbc()". This resolves a kernel BUG reported by syzbot. Since there are two flaws involved, I've made each one a separate patch. The first patch alone resolves the syzbot-reported bug, but I think both fixes should be sent to stable, so I've tagged them as such. This patch (of 2): Syzbot has reported a kernel bug in submit_bh_wbc() when writing file data to a nilfs2 file system whose metadata is corrupted. There are two flaws involved in this issue. The first flaw is that when nilfs_get_block() locates a data block using btree or direct mapping, if the disk address translation routine nilfs_dat_translate() fails with internal code -ENOENT due to DAT metadata corruption, it can be passed back to nilfs_get_block(). This causes nilfs_get_block() to misidentify an existing block as non-existent, causing both data block lookup and insertion to fail inconsistently. The second flaw is that nilfs_get_block() returns a successful status in this inconsistent state. This causes the caller __block_write_begin_int() or others to request a read even though the buffer is not mapped, resulting in a BUG_ON check for the BH_Mapped flag in submit_bh_wbc() failing. This fixes the first issue by changing the return value to code -EINVAL when a conversion using DAT fails with code -ENOENT, avoiding the conflicting condition that leads to the kernel bug described above. Here, code -EINVAL indicates that metadata corruption was detected during the block lookup, which will be properly handled as a file system error and converted to -EIO when passing through the nilfs2 bmap layer.

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected c3a7abf06ce719a51139e62a034590be99abbc2c before b67189690eb4b7ecc84ae16fa1e880e0123eaa35; affected c3a7abf06ce719a51139e62a034590be99abbc2c before 9cbe1ad5f4354f4df1445e5f4883983328cd6d8e; affected c3a7abf06ce719a51139e62a034590be99abbc2c before c3b5c5c31e723b568f83d8cafab8629d9d830ffb; affected c3a7abf06ce719a51139e62a034590be99abbc2c before 2e2619ff5d0def4bb6c2037a32a6eaa28dd95c84; affected c3a7abf06ce719a51139e62a034590be99abbc2c before 46b832e09d43b394ac0f6d9485d2b1a06593f0b7; affected c3a7abf06ce719a51139e62a034590be99abbc2c before f69e81396aea66304d214f175aa371f1b5578862; affected c3a7abf06ce719a51139e62a034590be99abbc2c before a8e4d098de1c0f4c5c1f2ed4633a860f0da6d713; affected c3a7abf06ce719a51139e62a034590be99abbc2c before 82827ca21e7c8a91384c5baa656f78a5adfa4ab4; affected c3a7abf06ce719a51139e62a034590be99abbc2c before f2f26b4a84a0ef41791bd2d70861c8eac748f4ba
Linux / Linuxaffected 2.6.31; unaffected 0 before 2.6.31; unaffected 4.19.312 through 4.19.*; unaffected 5.4.274 through 5.4.*; unaffected 5.10.215 through 5.10.*; unaffected 5.15.154 through 5.15.*; unaffected 6.1.84 through 6.1.*; unaffected 6.6.24 through 6.6.*; unaffected 6.7.12 through 6.7.*; unaffected 6.8.3 through 6.8.*; unaffected 6.9 through *

CWE

No CWE identifiers supplied.

References

ADP enrichment

CISA-ADP

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No references supplied.

CVE

No English description supplied.