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commit2d186afd04upstream. Syzbot reported shift-out-of-bounds bug in profile_init(). The problem was in incorrect prof_shift. Since prof_shift value comes from userspace we need to clamp this value into [0, BITS_PER_LONG -1] boundaries. Second possible shiht-out-of-bounds was found by Tetsuo: sample_step local variable in read_profile() had "unsigned int" type, but prof_shift allows to make a BITS_PER_LONG shift. So, to prevent possible shiht-out-of-bounds sample_step type was changed to "unsigned long". Also, "unsigned short int" will be sufficient for storing [0, BITS_PER_LONG] value, that's why there is no need for "unsigned long" prof_shift. Link: https://lkml.kernel.org/r/20210813140022.5011-1-paskripkin@gmail.com Fixes:1da177e4c3("Linux-2.6.12-rc2") Reported-and-tested-by: syzbot+e68c89a9510c159d9684@syzkaller.appspotmail.com Suggested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>