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authorLinus Torvalds <torvalds@linux-foundation.org>2022-08-03 13:59:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-08-03 13:59:15 -0700
commitd9b58ab789b053b70dc475f1efda124857f10aa2 (patch)
treef43c705e4417e65811de57f38b5a85cc9e7812d9 /lib
parent5264406cdb66c7003eb3edf53c9773b1b20611b9 (diff)
parentc3497fd009ef2c59eea60d21c3ac22de3585ed7d (diff)
Merge tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull copy_to_iter_mc fix from Al Viro: "Backportable fix for copy_to_iter_mc() - the second part of iov_iter work will pretty much overwrite this, but would be much harder to backport" * tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fix short copy handling in copy_mc_pipe_to_iter()
Diffstat (limited to 'lib')
-rw-r--r--lib/iov_iter.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 58648fcd9a88..0e0be334dbee 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -521,6 +521,7 @@ static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes,
struct pipe_inode_info *pipe = i->pipe;
unsigned int p_mask = pipe->ring_size - 1;
unsigned int i_head;
+ unsigned int valid = pipe->head;
size_t n, off, xfer = 0;
if (!sanity(i))
@@ -534,11 +535,17 @@ static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes,
rem = copy_mc_to_kernel(p + off, addr + xfer, chunk);
chunk -= rem;
kunmap_local(p);
- i->head = i_head;
- i->iov_offset = off + chunk;
- xfer += chunk;
- if (rem)
+ if (chunk) {
+ i->head = i_head;
+ i->iov_offset = off + chunk;
+ xfer += chunk;
+ valid = i_head + 1;
+ }
+ if (rem) {
+ pipe->bufs[i_head & p_mask].len -= rem;
+ pipe_discard_from(pipe, valid);
break;
+ }
n -= chunk;
off = 0;
i_head++;