Race condition in Linux kernel - CVE-2024-56686

Detailed vulnerability description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a race condition within the MODULE_ALIAS(), __ext4_read_bh(), ext4_read_bh_nowait(), ext4_read_bh(), ext4_read_bh_lock() and ext4_sb_breadahead_unmovable() functions in fs/ext4/super.c, within the ext4_get_bitmap() function in fs/ext4/resize.c, within the mext_page_mkuptodate() function in fs/ext4/move_extent.c, within the read_mmp_block() function in fs/ext4/mmp.c, within the trace_ext4_load_inode() function in fs/ext4/inode.c, within the ext4_get_branch() function in fs/ext4/indirect.c, within the ext4_read_inode_bitmap() function in fs/ext4/ialloc.c, within the __read_extent_tree_block() function in fs/ext4/extents.c, within the ext4_read_block_bitmap_nowait() and ext4_wait_block_bitmap() functions in fs/ext4/balloc.c. A local user can escalate privileges on the system.

How to mitigate CVE-2024-56686

Sources

• https://git.kernel.org/stable/c/25a5acf88fed59e060405bbb48098f4a3a2c2adc
• https://git.kernel.org/stable/c/2f3d93e210b9c2866c8b3662adae427d5bf511ec
• https://git.kernel.org/stable/c/61832ee7fa2fbd569d129379e795038abfb0d128
• https://git.kernel.org/stable/c/77035e4d27e15f87ea55929c8bb8fb1970129e2f
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.6.64