tty: protect tty_write from odd low-level tty disciplines
Al root-caused a new warning from syzbot to the ttyprintk tty driver returning a write count larger than the data the tty layer actually gave it. Which confused the tty write code mightily, and with the new iov_iter based code, caused a WARNING in iov_iter_revert(). syzbot correctly bisected the source of the new warning to commit 9bb48c82 ("tty: implement write_iter"), but the oddity goes back much further, it just didn't get caught by anything before. Reported-by:<syzbot+3d2c27c2b7dc2a94814d@syzkaller.appspotmail.com> Fixes: 9bb48c82 ("tty: implement write_iter") Debugged-by:
Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
parent
2c405d1a
Please register or sign in to comment