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authorOmar Sandoval <osandov@fb.com>2023-11-17 13:38:46 -0800
committerChristian Brauner <brauner@kernel.org>2023-11-18 16:42:07 +0100
commitfe2c34bab6d46469ad3095955dc37e984dc24e38 (patch)
tree7e3ba304da7748545e8a5ec5cedab2baf58c6216
parent8a924db2d7b5eb69ba08b1a0af46e9f1359a9bdf (diff)
iov_iter: fix copy_page_to_iter_nofault()
The recent conversion to inline functions made two mistakes: 1. It tries to copy the full amount requested (bytes), not just what's available in the kmap'd page (n). 2. It's not applying the offset in the first page. Note that copy_page_to_iter_nofault() is only used by /proc/kcore. This was detected by drgn's test suite. Fixes: f1982740f5e7 ("iov_iter: Convert iterate*() to inline funcs") Signed-off-by: Omar Sandoval <osandov@fb.com> Link: https://lore.kernel.org/r/c1616e06b5248013cbbb1881bb4fef85a7a69ccb.1700257019.git.osandov@fb.com Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
-rw-r--r--lib/iov_iter.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index de7d11cf4c63..8ff6824a1005 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -409,7 +409,7 @@ size_t copy_page_to_iter_nofault(struct page *page, unsigned offset, size_t byte
void *kaddr = kmap_local_page(page);
size_t n = min(bytes, (size_t)PAGE_SIZE - offset);
- n = iterate_and_advance(i, bytes, kaddr,
+ n = iterate_and_advance(i, n, kaddr + offset,
copy_to_user_iter_nofault,
memcpy_to_iter);
kunmap_local(kaddr);