[PATCH] fix kmalloc bug in bpf_prog_alloc_no_stats

Hithashree Bojanala posted 1 patch 1 week ago
kernel/bpf/core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
[PATCH] fix kmalloc bug in bpf_prog_alloc_no_stats
Posted by Hithashree Bojanala 1 week ago
From: Hithashri Bojanala <bojanalahithashri@gmail.com>

fix https://syzkaller.appspot.com/bug?extid=d4264133b3e51212ea30
vmalloc doesnt support __GFP_ACCOUNT
---
 kernel/bpf/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index d595fe512498..ffe2658ce165 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -263,7 +263,8 @@ struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 	if (pages <= fp_old->pages)
 		return fp_old;
 
-	fp = __vmalloc(size, gfp_flags);
+	/*vmalloc doesn't support __GFP_ACCOUNT, so strip it for the vmalloc call */
+	fp = __vmalloc(size, gfp_flags & ~__GFP_ACCOUNT);
 	if (fp) {
 		memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
 		fp->pages = pages;
-- 
2.47.0
Re: [PATCH] fix kmalloc bug in bpf_prog_alloc_no_stats
Posted by Matthew Wilcox 1 week ago
On Mon, Nov 24, 2025 at 01:05:20PM -0500, Hithashree Bojanala wrote:
> From: Hithashri Bojanala <bojanalahithashri@gmail.com>
> 
> fix https://syzkaller.appspot.com/bug?extid=d4264133b3e51212ea30
> vmalloc doesnt support __GFP_ACCOUNT

NAK.
https://lore.kernel.org/linux-mm/20251117173530.43293-1-vishal.moola@gmail.com/
fixed this.  Discussion here:
https://lore.kernel.org/linux-mm/aRXeK_C44xGb3ovg@milan/