1.5 KiB
CVE-2024-36966
Description
In the Linux kernel, the following vulnerability has been resolved:erofs: reliably distinguish block based and fscache modeWhen erofs_kill_sb() is called in block dev based mode, s_bdev may nothave been initialised yet, and if CONFIG_EROFS_FS_ONDEMAND is enabled,it will be mistaken for fscache mode, and then attempt to free an anon_devthat has never been allocated, triggering the following warning:============================================ida_free called for id=0 which is not allocated.WARNING: CPU: 14 PID: 926 at lib/idr.c:525 ida_free+0x134/0x140Modules linked in:CPU: 14 PID: 926 Comm: mount Not tainted 6.9.0-rc3-dirty #630RIP: 0010:ida_free+0x134/0x140Call Trace: erofs_kill_sb+0x81/0x90 deactivate_locked_super+0x35/0x80 get_tree_bdev+0x136/0x1e0 vfs_get_tree+0x2c/0xf0 do_new_mount+0x190/0x2f0 [...]============================================Now when erofs_kill_sb() is called, erofs_sb_info must have beeninitialised, so use sbi->fsid to distinguish between the two modes.
POC
Reference
No PoCs from references.