6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andrea Righi <andrea.righi@xxxxxxxxxxxxx>
[ Upstream commit 3737df782c740b944912ed93420c57344b1cf864 ]
Use a similar approach as commit a419beac4a07 ("module/decompress: use
vmalloc() for zstd decompression workspace") and replace kmalloc() with
vmalloc() also for the gzip module decompression workspace.
In this case the workspace is represented by struct inflate_workspace
that can be fairly large for kmalloc() and it can potentially lead to
allocation errors on certain systems:
$ pahole inflate_workspace
struct inflate_workspace {
struct inflate_state inflate_state; /* 0 9544 */
/* --- cacheline 149 boundary (9536 bytes) was 8 bytes ago --- */
unsigned char working_window[32768]; /* 9544 32768 */
/* size: 42312, cachelines: 662, members: 2 */
/* last cacheline: 8 bytes */
};
Considering that there is no need to use continuous physical memory,
simply switch to vmalloc() to provide a more reliable in-kernel module
decompression.
Fixes: b1ae6dc41eaa ("module: add in-kernel support for decompressing")
Signed-off-by: Andrea Righi <andrea.righi@xxxxxxxxxxxxx>
Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
kernel/module/decompress.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/module/decompress.c b/kernel/module/decompress.c
index 720e719253cd1..e1e9f69c5dd16 100644
--- a/kernel/module/decompress.c
+++ b/kernel/module/decompress.c
@@ -100,7 +100,7 @@ static ssize_t module_gzip_decompress(struct load_info *info,
s.next_in = buf + gzip_hdr_len;
s.avail_in = size - gzip_hdr_len;
- s.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
+ s.workspace = vmalloc(zlib_inflate_workspacesize());
if (!s.workspace)
return -ENOMEM;
@@ -138,7 +138,7 @@ static ssize_t module_gzip_decompress(struct load_info *info,
out_inflate_end:
zlib_inflateEnd(&s);
out:
- kfree(s.workspace);
+ vfree(s.workspace);
return retval;
}
#elif CONFIG_MODULE_COMPRESS_XZ
--
2.42.0
