safesetid: check size of policy writes
[ Upstream commit f09ff307c7299392f1c88f763299e24bc99811c7 ] syzbot attempts to write a buffer with a large size to a sysfs entry with writes handled by handle_policy_update(), triggering a warning in kmalloc. Check the size specified for write buffers before allocating. Reported-by: syzbot+4eb7a741b3216020043a@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=4eb7a741b3216020043a Signed-off-by: Leo Stone <leocstone@gmail.com> [PM: subject tweak] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
committed by
Greg Kroah-Hartman
parent
4723df76ac
commit
96fae5bd15
@@ -143,6 +143,9 @@ static ssize_t handle_policy_update(struct file *file,
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char *buf, *p, *end;
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char *buf, *p, *end;
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int err;
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int err;
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if (len >= KMALLOC_MAX_SIZE)
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return -EINVAL;
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pol = kmalloc(sizeof(struct setid_ruleset), GFP_KERNEL);
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pol = kmalloc(sizeof(struct setid_ruleset), GFP_KERNEL);
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if (!pol)
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if (!pol)
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return -ENOMEM;
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return -ENOMEM;
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