This is a note to let you know that I've just added the patch titled
xdp: Remove WARN() from __xdp_reg_mem_model()
to the 6.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xdp-remove-warn-from-__xdp_reg_mem_model.patch
and it can be found in the queue-6.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 351edcea01a50af3aff1b2dd75985797f3993b32
Author: Daniil Dulov <d.dulov@xxxxxxxxxx>
Date: Mon Jun 24 11:07:47 2024 +0300
xdp: Remove WARN() from __xdp_reg_mem_model()
[ Upstream commit 7e9f79428372c6eab92271390851be34ab26bfb4 ]
syzkaller reports a warning in __xdp_reg_mem_model().
The warning occurs only if __mem_id_init_hash_table() returns an error. It
returns the error in two cases:
1. memory allocation fails;
2. rhashtable_init() fails when some fields of rhashtable_params
struct are not initialized properly.
The second case cannot happen since there is a static const rhashtable_params
struct with valid fields. So, warning is only triggered when there is a
problem with memory allocation.
Thus, there is no sense in using WARN() to handle this error and it can be
safely removed.
WARNING: CPU: 0 PID: 5065 at net/core/xdp.c:299 __xdp_reg_mem_model+0x2d9/0x650 net/core/xdp.c:299
CPU: 0 PID: 5065 Comm: syz-executor883 Not tainted 6.8.0-syzkaller-05271-gf99c5f563c17 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:__xdp_reg_mem_model+0x2d9/0x650 net/core/xdp.c:299
Call Trace:
xdp_reg_mem_model+0x22/0x40 net/core/xdp.c:344
xdp_test_run_setup net/bpf/test_run.c:188 [inline]
bpf_test_run_xdp_live+0x365/0x1e90 net/bpf/test_run.c:377
bpf_prog_test_run_xdp+0x813/0x11b0 net/bpf/test_run.c:1267
bpf_prog_test_run+0x33a/0x3b0 kernel/bpf/syscall.c:4240
__sys_bpf+0x48d/0x810 kernel/bpf/syscall.c:5649
__do_sys_bpf kernel/bpf/syscall.c:5738 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5736 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5736
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
Found by Linux Verification Center (linuxtesting.org) with syzkaller.
Fixes: 8d5d88527587 ("xdp: rhashtable with allocator ID to pointer mapping")
Signed-off-by: Daniil Dulov <d.dulov@xxxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Acked-by: Jesper Dangaard Brouer <hawk@xxxxxxxxxx>
Link: https://lore.kernel.org/all/20240617162708.492159-1-d.dulov@xxxxxxxxxx
Link: https://lore.kernel.org/bpf/20240624080747.36858-1-d.dulov@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 41693154e426f..022c12059cf2f 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -295,10 +295,8 @@ static struct xdp_mem_allocator *__xdp_reg_mem_model(struct xdp_mem_info *mem,
mutex_lock(&mem_id_lock);
ret = __mem_id_init_hash_table();
mutex_unlock(&mem_id_lock);
- if (ret < 0) {
- WARN_ON(1);
+ if (ret < 0)
return ERR_PTR(ret);
- }
}
xdp_alloc = kzalloc(sizeof(*xdp_alloc), gfp);
