Steven Rostedt (Google) e5104cbb14 tracefs: Clear EVENT_INODE flag in tracefs_drop_inode() ... commit 0bcfd9aa4d upstream. When the inode is being dropped from the dentry, the TRACEFS_EVENT_INODE flag needs to be cleared to prevent a remount from calling eventfs_remount() on the tracefs_inode private data. There's a race between the inode is dropped (and the dentry freed) to where the inode is actually freed. If a remount happens between the two, the eventfs_inode could be accessed after it is freed (only the dentry keeps a ref count on it). Currently the TRACEFS_EVENT_INODE flag is cleared from the dentry iput() function. But this is incorrect, as it is possible that the inode has another reference to it. The flag should only be cleared when the inode is really being dropped and has no more references. That happens in the drop_inode callback of the inode, as that gets called when the last reference of the inode is released. Remove the tracefs_d_iput() function and move its logic to the more appropriate tracefs_drop_inode() callback function. Link: https://lore.kernel.org/linux-trace-kernel/20240523051539.908205106@goodmis.org Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Fixes: baa23a8d43 ("tracefs: Reset permissions on remount if permissions are options") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2024-06-16 13:47:48 +02:00
..
Makefile	eventfs: Implement eventfs dir creation functions	2023-07-30 18:13:33 -04:00
event_inode.c	eventfs: Keep the directories from having the same inode number as files	2024-06-16 13:47:47 +02:00
inode.c	tracefs: Clear EVENT_INODE flag in tracefs_drop_inode()	2024-06-16 13:47:48 +02:00
internal.h	eventfs: Create eventfs_root_inode to store dentry	2024-06-12 11:12:35 +02:00