linux/kernel/events
Hugh Dickins c17c3dc9d0 uprobes: __replace_page() avoid BUG in munlock_vma_page()
syzbot crashed on the VM_BUG_ON_PAGE(PageTail) in munlock_vma_page(), when
called from uprobes __replace_page().  Which of many ways to fix it?
Settled on not calling when PageCompound (since Head and Tail are equals
in this context, PageCompound the usual check in uprobes.c, and the prior
use of FOLL_SPLIT_PMD will have cleared PageMlocked already).

Fixes: 5a52c9df62 ("uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>	[5.4+]
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2008161338360.20413@eggly.anvils
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-21 09:52:53 -07:00
..
callchain.c uaccess: add force_uaccess_{begin,end} helpers 2020-08-12 10:57:59 -07:00
core.c Misc fixes, an expansion of perf syscall access to CAP_PERFMON privileged tools, 2020-08-15 10:34:24 -07:00
hw_breakpoint.c powerpc/watchpoint: Don't allow concurrent perf and ptrace events 2020-05-19 00:14:45 +10:00
internal.h perf/core: Replace zero-length array with flexible-array 2020-05-19 20:34:16 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ring_buffer.c perf: Make struct ring_buffer less ambiguous 2020-01-13 13:19:38 -05:00
uprobes.c uprobes: __replace_page() avoid BUG in munlock_vma_page() 2020-08-21 09:52:53 -07:00