CVE-2024-53130
nilfs2: fix null-ptr-deref in block_dirty_buffer tracepoint
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nilfs2: fix null-ptr-deref in block_dirty_buffer tracepoint
In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix null-ptr-deref in block_dirty_buffer tracepoint When using the "block:block_dirty_buffer" tracepoint, mark_buffer_dirty() may cause a NULL pointer dereference, or a general protection fault when KASAN is enabled. This happens because, since the tracepoint was added in mark_buffer_dirty(), it references the dev_t member bh->b_bdev->bd_dev regardless of whether the buffer head has a pointer to a block_device structure. In the current implementation, nilfs_grab_buffer(), which grabs a buffer to read (or create) a block of metadata, including b-tree node blocks, does not set the block device, but instead does so only if the buffer is not in the "uptodate" state for each of its caller block reading functions. However, if the uptodate flag is set on a folio/page, and the buffer heads are detached from it by try_to_free_buffers(), and new buffer heads are then attached by create_empty_buffers(), the uptodate flag may be restored to each buffer without the block device being set to bh->b_bdev, and mark_buffer_dirty() may be called later in that state, resulting in the bug mentioned above. Fix this issue by making nilfs_grab_buffer() always set the block device of the super block structure to the buffer head, regardless of the state of the buffer's uptodate flag.
Reserved 2024-11-19 | Published 2024-12-04 | Updated 2024-12-19 | Assigner Linuxgit.kernel.org/...c/7af3309c7a2ef26831a67125b11c34a7e01c1b2a
git.kernel.org/...c/0ce59fb1c73fdd5b6028226aeb46259a0cdc0957
git.kernel.org/...c/0a5014ad37c77ac6a2c525137c00a0e1724f6020
git.kernel.org/...c/d904e4d845aafbcfd8a40c1df7d999f02f062be8
git.kernel.org/...c/86b19031dbc79abc378dfae357f6ea33ebeb0c95
git.kernel.org/...c/b0e4765740040c44039282057ecacd7435d1d2ba
git.kernel.org/...c/ffc440a76a0f476a7e6ea838ec0dc8e9979944d1
git.kernel.org/...c/2026559a6c4ce34db117d2db8f710fe2a9420d5a
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