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| author | Pavel Skripkin <paskripkin@gmail.com> | 2021-12-30 17:26:49 +0300 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2022-01-18 09:52:41 +0300 |
| commit | 2b6dd600dd72573c23ea180b5b0b2f1813405882 (patch) | |
| tree | ddd26905a18679cd5860f0b3e1ad926348c7e52e | |
| parent | 269332997a160b3785690a32d2c5496bce7dae51 (diff) | |
| download | linux-2b6dd600dd72573c23ea180b5b0b2f1813405882.tar.xz | |
udmabuf: validate ubuf->pagecount
Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The
problem was in ubuf->pages == ZERO_PTR.
ubuf->pagecount is calculated from arguments passed from user-space. If
user creates udmabuf with list.size == 0 then ubuf->pagecount will be
also equal to zero; it causes kmalloc_array() to return ZERO_PTR.
Fix it by validating ubuf->pagecount before passing it to
kmalloc_array().
Fixes: fbb0de795078 ("Add udmabuf misc device")
Reported-and-tested-by: syzbot+2c56b725ec547fa9cb29@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20211230142649.23022-1-paskripkin@gmail.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
| -rw-r--r-- | drivers/dma-buf/udmabuf.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index c57a609db75b..e7330684d3b8 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -190,6 +190,10 @@ static long udmabuf_create(struct miscdevice *device, if (ubuf->pagecount > pglimit) goto err; } + + if (!ubuf->pagecount) + goto err; + ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(*ubuf->pages), GFP_KERNEL); if (!ubuf->pages) { |