UPSTREAM: erofs: avoid infinite loop in z_erofs_do_read_page() when reading beyond EOF
z_erofs_do_read_page() may loop infinitely due to the inappropriate
truncation in the below statement. Since the offset is 64 bits and min_t()
truncates the result to 32 bits. The solution is to replace unsigned int
with a 64-bit type, such as erofs_off_t.
cur = end - min_t(unsigned int, offset + end - map->m_la, end);
- For example:
- offset = 0x400160000
- end = 0x370
- map->m_la = 0x160370
- offset + end - map->m_la = 0x400000000
- offset + end - map->m_la = 0x00000000 (truncated as unsigned int)
- Expected result:
- cur = 0
- Actual result:
- cur = 0x370
Signed-off-by: Chunhai Guo <guochunhai@vivo.com>
Fixes: 3883a79abd02 ("staging: erofs: introduce VLE decompression support")
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230710093410.44071-1-guochunhai@vivo.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
(cherry picked from commit 8191213a5835b0317c5e4d0d337ae1ae00c75253
https://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git dev)
Bug: 296824280
Bug: 310543513
Change-Id: I152508ba4c0eb83aeae5d753e22b0ca8d3ada56d
Signed-off-by: sunshijie <sunshijie@xiaomi.corp-partner.google.com>
Signed-off-by: sunshijie <sunshijie@xiaomi.com>
(cherry picked from commit ffaab71302ca81ac4addbc63f5a81be37988595a)
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 6b5bb7c..1799463 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -825,7 +825,7 @@
tight &= (clt->mode >= COLLECT_PRIMARY_HOOKED &&
clt->mode != COLLECT_PRIMARY_FOLLOWED_NOINPLACE);
- cur = end - min_t(unsigned int, offset + end - map->m_la, end);
+ cur = end - min_t(erofs_off_t, offset + end - map->m_la, end);
if (!(map->m_flags & EROFS_MAP_MAPPED)) {
zero_user_segment(page, cur, end);
goto next_part;
