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| author | Marcelo Henrique Cerri <marcelo.cerri@canonical.com> | 2021-07-01 04:54:38 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-28 10:12:35 +0300 |
| commit | cb0fc2a32a10375ca07c2ad067fc2c1e74585035 (patch) | |
| tree | e71eed932058995a9a4e6d9c9a1153f063a81c43 | |
| parent | fe6b2deca355bd5ab554eb0c6ce50bc91cc0f92e (diff) | |
| download | linux-cb0fc2a32a10375ca07c2ad067fc2c1e74585035.tar.xz | |
proc: Avoid mixing integer types in mem_rw()
[ Upstream commit d238692b4b9f2c36e35af4c6e6f6da36184aeb3e ]
Use size_t when capping the count argument received by mem_rw(). Since
count is size_t, using min_t(int, ...) can lead to a negative value
that will later be passed to access_remote_vm(), which can cause
unexpected behavior.
Since we are capping the value to at maximum PAGE_SIZE, the conversion
from size_t to int when passing it to access_remote_vm() as "len"
shouldn't be a problem.
Link: https://lkml.kernel.org/r/20210512125215.3348316-1-marcelo.cerri@canonical.com
Reviewed-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Souza Cascardo <cascardo@canonical.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | fs/proc/base.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index b1ff8eb61802..4d68f5a9e4aa 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -887,7 +887,7 @@ static ssize_t mem_rw(struct file *file, char __user *buf, flags |= FOLL_WRITE; while (count > 0) { - int this_len = min_t(int, count, PAGE_SIZE); + size_t this_len = min_t(size_t, count, PAGE_SIZE); if (write && copy_from_user(page, buf, this_len)) { copied = -EFAULT; |