| Message ID | 20250306132855.2030-1-zhiyuzhang999@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | squashfs: Fix invalid pointer dereference in squashfs_cache_delete | expand |
On 06/03/2025 13:28, Zhiyu Zhang wrote: > When mounting a squashfs fails, squashfs_cache_init() may return an error > pointer (e.g., -ENOMEM) instead of NULL. However, squashfs_cache_delete() > only checks for a NULL cache, and attempts to dereference the invalid > pointer. This leads to a kernel crash (BUG: unable to handle kernel paging > request in squashfs_cache_delete). > > This patch fixes the issue by checking IS_ERR(cache) before accessing it. > > Fixes: 49ff29240ebb ("squashfs: make squashfs_cache_init() return ERR_PTR(-ENOMEM)") > Reported-by: Zhiyu Zhang <zhiyuzhang999@gmail.com> > Closes: https://lore.kernel.org/linux-fsdevel/CALf2hKvaq8B4u5yfrE+BYt7aNguao99mfWxHngA+=o5hwzjdOg@mail.gmail.com/ > Tested-by: Zhiyu Zhang <zhiyuzhang999@gmail.com> > Signed-off-by: Zhiyu Zhang <zhiyuzhang999@gmail.com> > --- > fs/squashfs/cache.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/squashfs/cache.c b/fs/squashfs/cache.c > index 4db0d2b0aab8..181260e72680 100644 > --- a/fs/squashfs/cache.c > +++ b/fs/squashfs/cache.c > @@ -198,7 +198,7 @@ void squashfs_cache_delete(struct squashfs_cache *cache) > { > int i, j; > > - if (cache == NULL) > + if (IS_ERR(cache) || cache == NULL) > return; > > for (i = 0; i < cache->entries; i++) { Looks good to me. Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
diff --git a/fs/squashfs/cache.c b/fs/squashfs/cache.c index 4db0d2b0aab8..181260e72680 100644 --- a/fs/squashfs/cache.c +++ b/fs/squashfs/cache.c @@ -198,7 +198,7 @@ void squashfs_cache_delete(struct squashfs_cache *cache) { int i, j; - if (cache == NULL) + if (IS_ERR(cache) || cache == NULL) return; for (i = 0; i < cache->entries; i++) {
When mounting a squashfs fails, squashfs_cache_init() may return an error pointer (e.g., -ENOMEM) instead of NULL. However, squashfs_cache_delete() only checks for a NULL cache, and attempts to dereference the invalid pointer. This leads to a kernel crash (BUG: unable to handle kernel paging request in squashfs_cache_delete). This patch fixes the issue by checking IS_ERR(cache) before accessing it. Fixes: 49ff29240ebb ("squashfs: make squashfs_cache_init() return ERR_PTR(-ENOMEM)") Reported-by: Zhiyu Zhang <zhiyuzhang999@gmail.com> Closes: https://lore.kernel.org/linux-fsdevel/CALf2hKvaq8B4u5yfrE+BYt7aNguao99mfWxHngA+=o5hwzjdOg@mail.gmail.com/ Tested-by: Zhiyu Zhang <zhiyuzhang999@gmail.com> Signed-off-by: Zhiyu Zhang <zhiyuzhang999@gmail.com> --- fs/squashfs/cache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)