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authorMiklos Szeredi <mszeredi@redhat.com>2020-02-06 16:39:28 +0100
committerMiklos Szeredi <mszeredi@redhat.com>2020-02-06 16:39:28 +0100
commit2f1398291bf35fe027914ae7a9610d8e601fbfde (patch)
treebf2d245ba2d6ea3937423cc5080228474b759a76 /fs/fuse
parentf658adeea45e430a24c7a157c3d5448925ac2038 (diff)
fuse: don't overflow LLONG_MAX with end offset
Handle the special case of fuse_readpages() wanting to read the last page of a hugest file possible and overflowing the end offset in the process. This is basically to unbreak xfstests:generic/525 and prevent filesystems from doing bad things with an overflowing offset. Reported-by: Xiao Yang <ice_yangxiao@163.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/fuse')
-rw-r--r--fs/fuse/file.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 695369f46f92..3dd37a998ea9 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -803,6 +803,10 @@ static int fuse_do_readpage(struct file *file, struct page *page)
attr_ver = fuse_get_attr_version(fc);
+ /* Don't overflow end offset */
+ if (pos + (desc.length - 1) == LLONG_MAX)
+ desc.length--;
+
fuse_read_args_fill(&ia, file, pos, desc.length, FUSE_READ);
res = fuse_simple_request(fc, &ia.ap.args);
if (res < 0)
@@ -888,6 +892,14 @@ static void fuse_send_readpages(struct fuse_io_args *ia, struct file *file)
ap->args.out_pages = true;
ap->args.page_zeroing = true;
ap->args.page_replace = true;
+
+ /* Don't overflow end offset */
+ if (pos + (count - 1) == LLONG_MAX) {
+ count--;
+ ap->descs[ap->num_pages - 1].length--;
+ }
+ WARN_ON((loff_t) (pos + count) < 0);
+
fuse_read_args_fill(ia, file, pos, count, FUSE_READ);
ia->read.attr_ver = fuse_get_attr_version(fc);
if (fc->async_read) {