diff options
| author | Yicong Yang <yangyicong@hisilicon.com> | 2020-11-21 22:17:19 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-11-24 13:29:19 +0100 |
| commit | 8a411bb0d73f8916670fac78a8691c717bbda816 (patch) | |
| tree | 7db064995791e992e66afd349a1aef063b1f412c /fs/libfs.c | |
| parent | 9d1b5a8c720e6945834e7dc2c4c1e9916e2fb67c (diff) | |
libfs: fix error cast of negative value in simple_attr_write()
[ Upstream commit 488dac0c9237647e9b8f788b6a342595bfa40bda ]
The attr->set() receive a value of u64, but simple_strtoll() is used for
doing the conversion. It will lead to the error cast if user inputs a
negative value.
Use kstrtoull() instead of simple_strtoll() to convert a string got from
the user to an unsigned value. The former will return '-EINVAL' if it
gets a negetive value, but the latter can't handle the situation
correctly. Make 'val' unsigned long long as what kstrtoull() takes,
this will eliminate the compile warning on no 64-bit architectures.
Fixes: f7b88631a897 ("fs/libfs.c: fix simple_attr_write() on 32bit machines")
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/1605341356-11872-1-git-send-email-yangyicong@hisilicon.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/libfs.c')
| -rw-r--r-- | fs/libfs.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/libfs.c b/fs/libfs.c index 5fd9cc0e2ac9..247b58a68240 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -887,7 +887,7 @@ ssize_t simple_attr_write(struct file *file, const char __user *buf, size_t len, loff_t *ppos) { struct simple_attr *attr; - u64 val; + unsigned long long val; size_t size; ssize_t ret; @@ -905,7 +905,9 @@ ssize_t simple_attr_write(struct file *file, const char __user *buf, goto out; attr->set_buf[size] = '\0'; - val = simple_strtoll(attr->set_buf, NULL, 0); + ret = kstrtoull(attr->set_buf, 0, &val); + if (ret) + goto out; ret = attr->set(attr->data, val); if (ret == 0) ret = len; /* on success, claim we got the whole input */ |