Kees Cook 8c90c4e619 printk: ringbuffer: Fix truncating buffer size min_t cast ... commit 53e9e33ede37a247d926db5e4a9e56b55204e66c upstream. If an output buffer size exceeded U16_MAX, the min_t(u16, ...) cast in copy_data() was causing writes to truncate. This manifested as output bytes being skipped, seen as %NUL bytes in pstore dumps when the available record size was larger than 65536. Fix the cast to no longer truncate the calculation. Cc: Petr Mladek <pmladek@suse.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: John Ogness <john.ogness@linutronix.de> Reported-by: Vijay Balakrishna <vijayb@linux.microsoft.com> Link: https://lore.kernel.org/lkml/d8bb1ec7-a4c5-43a2-9de0-9643a70b899f@linux.microsoft.com/ Fixes: b6cf8b3f33 ("printk: add lockless ringbuffer") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Vijay Balakrishna <vijayb@linux.microsoft.com> Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck Reviewed-by: Tyler Hicks (Microsoft) <code@tyhicks.com> Tested-by: Tyler Hicks (Microsoft) <code@tyhicks.com> Reviewed-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230811054528.never.165-kees@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2023-09-19 12:20:21 +02:00
..
braille.c	printk: Replace strncmp() with str_has_prefix()	2019-08-16 09:54:08 +02:00
braille.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
console_cmdline.h	printk: Fix preferred console selection with multiple matches	2020-02-18 09:34:42 +01:00
internal.h	printk: move dictionary keys to dev_printk_info	2020-09-22 11:27:48 +02:00
Makefile	printk: add lockless ringbuffer	2020-07-10 08:48:19 +02:00
printk_ringbuffer.c	printk: ringbuffer: Fix truncating buffer size min_t cast	2023-09-19 12:20:21 +02:00
printk_ringbuffer.h	printk: avoid and/or handle record truncation	2020-09-30 13:30:28 +02:00
printk_safe.c	printk: fix deadlock when kernel panic	2021-03-04 11:38:41 +01:00
printk.c	printk: fix return value of printk.devkmsg __setup handler	2022-04-08 14:40:08 +02:00