AcoSail/kernel_optimize_test
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sysctl: reject gigantic reads/write to sysctl files

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Instead of triggering a WARN_ON deep down in the page allocator just
give up early on allocations that are way larger than the usual sysctl
values.

Fixes: 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Christoph Hellwig 2020-06-09 19:08:19 +02:00 committed by Al Viro
parent 8c46fa9682
commit ef9d965bc8
1 changed files with 4 additions and 0 deletions
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4
fs/proc/proc_sysctl.c
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@ -564,6 +564,10 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
if (!table->proc_handler)
goto out;
/* don't even try if the size is too large */
if (count > KMALLOC_MAX_SIZE)
return -ENOMEM;
if (write) {
kbuf = memdup_user_nul(ubuf, count);
if (IS_ERR(kbuf)) {