31 lines
732 B
Plaintext
31 lines
732 B
Plaintext
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From: Dean Roe <roe@sgi.com>
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Subject: Prevent NULL pointer deref in grab_swap_token
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References: 159260
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Patch-mainline: not yet
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grab_swap_token() assumes that the current process has an mm struct,
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which is not true for kernel threads invoking get_user_pages(). Since
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this should be extremely rare, just return from grab_swap_token()
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without doing anything.
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Signed-off-by: Dean Roe <roe@sgi.com>
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Acked-by: mason@suse.de
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Acked-by: okir@suse.de
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mm/thrash.c | 3 +++
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1 file changed, 3 insertions(+)
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--- a/mm/thrash.c
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+++ b/mm/thrash.c
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@@ -31,6 +31,9 @@ void grab_swap_token(struct mm_struct *m
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int current_interval;
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global_faults++;
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+ if (mm == NULL)
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+ return;
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+
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current_interval = global_faults - mm->faultstamp;
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