6.6-stable review patch. If anyone has any objections, please let me know.
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From: Andrea Righi andrea.righi@canonical.com
[ 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@canonical.com Signed-off-by: Luis Chamberlain mcgrof@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 87440f714c0ca..4156d59be4408 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 defined(CONFIG_MODULE_COMPRESS_XZ)