From: Tetsuo Handa Date: Mon, 16 Dec 2024 10:38:40 +0000 (+0900) Subject: tomoyo: don't emit warning in tomoyo_write_control() X-Git-Tag: v6.14-rc1~137^2~2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3df7546fc03b8f004eee0b9e3256369f7d096685;p=thirdparty%2Fkernel%2Fstable.git tomoyo: don't emit warning in tomoyo_write_control() syzbot is reporting too large allocation warning at tomoyo_write_control(), for one can write a very very long line without new line character. To fix this warning, I use __GFP_NOWARN rather than checking for KMALLOC_MAX_SIZE, for practically a valid line should be always shorter than 32KB where the "too small to fail" memory-allocation rule applies. One might try to write a valid line that is longer than 32KB, but such request will likely fail with -ENOMEM. Therefore, I feel that separately returning -EINVAL when a line is longer than KMALLOC_MAX_SIZE is redundant. There is no need to distinguish over-32KB and over-KMALLOC_MAX_SIZE. Reported-by: syzbot+7536f77535e5210a5c76@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=7536f77535e5210a5c76 Reported-by: Leo Stone Closes: https://lkml.kernel.org/r/20241216021459.178759-2-leocstone@gmail.com Signed-off-by: Tetsuo Handa --- diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c index 5c7b059a332aa..972664962e8f6 100644 --- a/security/tomoyo/common.c +++ b/security/tomoyo/common.c @@ -2665,7 +2665,7 @@ ssize_t tomoyo_write_control(struct tomoyo_io_buffer *head, if (head->w.avail >= head->writebuf_size - 1) { const int len = head->writebuf_size * 2; - char *cp = kzalloc(len, GFP_NOFS); + char *cp = kzalloc(len, GFP_NOFS | __GFP_NOWARN); if (!cp) { error = -ENOMEM;