diff options
| author | Christoph Hellwig <hch@lst.de> | 2020-06-09 19:08:19 +0200 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2020-06-10 14:11:33 -0400 |
| commit | ef9d965bc8b6fce5bcc0ae76a4a5b3ed91ee81eb (patch) | |
| tree | b8c9350abed0e245cbda54b026158f78a977cbe0 /fs | |
| parent | 8c46fa96822c28ca81036e26c2d963f1fac9a961 (diff) | |
| download | lwn-ef9d965bc8b6fce5bcc0ae76a4a5b3ed91ee81eb.tar.gz lwn-ef9d965bc8b6fce5bcc0ae76a4a5b3ed91ee81eb.zip | |
sysctl: reject gigantic reads/write to sysctl files
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: 32927393dc1c ("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>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/proc/proc_sysctl.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index df2143e05c57..08c33bd1642d 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -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)) { |