CVE-2024-47699

Description

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix potential null-ptr-deref in nilfs_btree_insert() Patch series "nilfs2: fix potential issues with empty b-tree nodes". This series addresses three potential issues with empty b-tree nodes that can occur with corrupted filesystem images, including one recently discovered by syzbot. This patch (of 3): If a b-tree is broken on the device, and the b-tree height is greater than 2 (the level of the root node is greater than 1) even if the number of child nodes of the b-tree root is 0, a NULL pointer dereference occurs in nilfs_btree_prepare_insert(), which is called from nilfs_btree_insert(). This is because, when the number of child nodes of the b-tree root is 0, nilfs_btree_do_lookup() does not set the block buffer head in any of path[x].bp_bh, leaving it as the initial value of NULL, but if the level of the b-tree root node is greater than 1, nilfs_btree_get_nonroot_node(), which accesses the buffer memory of path[x].bp_bh, is called. Fix this issue by adding a check to nilfs_btree_root_broken(), which performs sanity checks when reading the root node from the device, to detect this inconsistency. Thanks to Lizhi Xu for trying to solve the bug and clarifying the cause early on.

PUBLISHED Reserved 2024-09-30 | Published 2024-10-21 | Updated 2025-11-03 | Assigner Linux

Product status

References

lists.debian.org/debian-lts-announce/2025/03/msg00002.html

lists.debian.org/debian-lts-announce/2025/01/msg00001.html

git.kernel.org/...c/2b78e9df10fb7f4e9d3d7a18417dd72fbbc1dfd0

git.kernel.org/...c/1d94dbdfbb64cc48d10dec65cc3c4fbf2497b343

git.kernel.org/...c/24bf40740a3da6b4056721da34997ae6938f3da1

git.kernel.org/...c/73d23ecf234b7a6d47fb883f2dabe10e3230b31d

git.kernel.org/...c/f68523e0f26faade18833fbef577a4295d8e2c94

git.kernel.org/...c/21839b6fbc3c41b3e374ecbdb0cabbbb2c53cf34

git.kernel.org/...c/db73500d3f0e558eb642aae1d4782e7726b4a03f

git.kernel.org/...c/3644554d308ddf2669e459a1551a7edf60b2d62b

git.kernel.org/...c/9403001ad65ae4f4c5de368bdda3a0636b51d51a

cve.org (CVE-2024-47699)

nvd.nist.gov (CVE-2024-47699)

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