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| author | Xiaomeng Tong <xiam0nd.tong@gmail.com> | 2022-03-27 14:22:02 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-24 17:24:23 +0200 |
| commit | 5ac11fe03a0a83042d1a040dbce4fa2fb5521e23 (patch) | |
| tree | f179414d05b5e03b835f2c923ab860777785ab1c | |
| parent | 4834f9898c7301a365acd02095793d55b519e5a8 (diff) | |
| download | linux-stable-5ac11fe03a0a83042d1a040dbce4fa2fb5521e23.tar.gz linux-stable-5ac11fe03a0a83042d1a040dbce4fa2fb5521e23.tar.bz2 linux-stable-5ac11fe03a0a83042d1a040dbce4fa2fb5521e23.zip | |
misc: fastrpc: fix an incorrect NULL check on list iterator
The bug is here:
if (!buf) {
The list iterator value 'buf' will *always* be set and non-NULL
by list_for_each_entry(), so it is incorrect to assume that the
iterator value will be NULL if the list is empty (in this case, the
check 'if (!buf) {' will always be false and never exit expectly).
To fix the bug, use a new variable 'iter' as the list iterator,
while use the original variable 'buf' as a dedicated pointer to
point to the found element.
Fixes: 2419e55e532de ("misc: fastrpc: add mmap/unmap support")
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Link: https://lore.kernel.org/r/20220327062202.5720-1-xiam0nd.tong@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/misc/fastrpc.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c index d80ada8cac09..4bdc8e0df657 100644 --- a/drivers/misc/fastrpc.c +++ b/drivers/misc/fastrpc.c @@ -1606,17 +1606,18 @@ static int fastrpc_req_munmap_impl(struct fastrpc_user *fl, struct fastrpc_req_munmap *req) { struct fastrpc_invoke_args args[1] = { [0] = { 0 } }; - struct fastrpc_buf *buf, *b; + struct fastrpc_buf *buf = NULL, *iter, *b; struct fastrpc_munmap_req_msg req_msg; struct device *dev = fl->sctx->dev; int err; u32 sc; spin_lock(&fl->lock); - list_for_each_entry_safe(buf, b, &fl->mmaps, node) { - if ((buf->raddr == req->vaddrout) && (buf->size == req->size)) + list_for_each_entry_safe(iter, b, &fl->mmaps, node) { + if ((iter->raddr == req->vaddrout) && (iter->size == req->size)) { + buf = iter; break; - buf = NULL; + } } spin_unlock(&fl->lock); |