x86/ioperm: Prevent NULL dereference on theoretical missing IO bitmap

Browse source

Outside the IOPL emulation path, the IO bitmap is always expected
to be allocated when TIF_IO_BITMAP is set. The paranoid WARN_ON_ONCE()
handles the case where the flag and the pointer got out of sync.
In this theoretical scenario, which presumes some other bug in the
code that triggers the WARN_ON_ONCe(), return early, instead of
continuing and dereferencing a NULL pointer.

[ mingo: Clarified the changelog. ]

Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: https://patch.msgid.link/20260615070115.4720-1-lirongqing@baidu.com

...

This commit is contained in:

Li RongQing 2026-06-15 15:01:15 +08:00 • committed by Ingo Molnar

parent 8cd9520d35

commit 2d36d3b451

1 changed files with 1 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

1

arch/x86/kernel/process.c

View file