We received a report[1] of kernel crashes when Cilium is used in XDP
mode with virtio_net after updating to newer kernels. After
investigating the reason it turned out that when using mergeable bufs
with an XDP program which adjusts xdp.data or xdp.data_meta page_to_buf()
calculates the build_skb address wrong because the offset can become less
than the headroom so it gets the address of the previous page (-X bytes
depending on how lower offset is):
page_to_skb: page addr ffff9eb2923e2000 buf ffff9eb2923e1ffc offset 252 headroom 256
This is a pr_err() I added in the beginning of page_to_skb which clearly
shows offset that is less than headroom by adding 4 bytes of metadata
via an xdp prog. The calculations done are:
receive_mergeable():
headroom = VIRTIO_XDP_HEADROOM; // VIRTIO_XDP_HEADROOM == 256 bytes
offset = xdp.data - page_address(xdp_page) -
vi->hdr_len - metasize;
page_to_skb():
p = page_address(page) + offset;
...
buf = p - headroom;
Now buf goes -4 bytes from the page's starting address as can be seen
above which is set as skb->head and skb->data by build_skb later. Depending
on what's done with the skb (when it's freed most often) we get all kinds
of corruptions and BUG_ON() triggers in mm[2]. We have to recalculate
the new headroom after the xdp program has run, similar to how offset
and len are recalculated. Headroom is directly related to
data_hard_start, data and data_meta, so we use them to get the new size.
The result is correct (similar pr_err() in page_to_skb, one case of
xdp_page and one case of virtnet buf):
a) Case with 4 bytes of metadata
[ 115.949641] page_to_skb: page addr ffff8b4dcfad2000 offset 252 headroom 252
[ 121.084105] page_to_skb: page addr ffff8b4dcf018000 offset 20732 headroom 252
b) Case of pushing data +32 bytes
[ 153.181401] page_to_skb: page addr ffff8b4dd0c4d000 offset 288 headroom 288
[ 158.480421] page_to_skb: page addr ffff8b4dd00b0000 offset 24864 headroom 288
c) Case of pushing data -33 bytes
[ 835.906830] page_to_skb: page addr ffff8b4dd3270000 offset 223 headroom 223
[ 840.839910] page_to_skb: page addr ffff8b4dcdd68000 offset 12511 headroom 223
Offset and headroom are equal because offset points to the start of
reserved bytes for the virtio_net header which are at buf start +
headroom, while data points at buf start + vnet hdr size + headroom so
when data or data_meta are adjusted by the xdp prog both the headroom size
and the offset change equally. We can use data_hard_start to compute the
new headroom after the xdp prog (linearized / page start case, the
virtnet buf case is similar just with bigger base offset):
xdp.data_hard_start = page_address + vnet_hdr
xdp.data = page_address + vnet_hdr + headroom
new headroom after xdp prog = xdp.data - xdp.data_hard_start - metasize
An example reproducer xdp prog[3] is below.
[1] https://github.com/cilium/cilium/issues/19453
[2] Two of the many traces:
[ 40.437400] BUG: Bad page state in process swapper/0 pfn:14940
[ 40.916726] BUG: Bad page state in process systemd-resolve pfn:053b7
[ 41.300891] kernel BUG at include/linux/mm.h:720!
[ 41.301801] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[ 41.302784] CPU: 1 PID: 1181 Comm: kubelet Kdump: loaded Tainted: G B W 5.18.0-rc1+ #37
[ 41.304458] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014
[ 41.306018] RIP: 0010:page_frag_free+0x79/0xe0
[ 41.306836] Code: 00 00 75 ea 48 8b 07 a9 00 00 01 00 74 e0 48 8b 47 48 48 8d 50 ff a8 01 48 0f 45 fa eb d0 48 c7 c6 18 b8 30 a6 e8 d7 f8 fc ff <0f> 0b 48 8d 78 ff eb bc 48 8b 07 a9 00 00 01 00 74 3a 66 90 0f b6
[ 41.310235] RSP: 0018:ffffac05c2a6bc78 EFLAGS: 00010292
[ 41.311201] RAX: 000000000000003e RBX: 0000000000000000 RCX: 0000000000000000
[ 41.312502] RDX: 0000000000000001 RSI: ffffffffa6423004 RDI: 00000000ffffffff
[ 41.313794] RBP: ffff993c98823600 R08: 0000000000000000 R09: 00000000ffffdfff
[ 41.315089] R10: ffffac05c2a6ba68 R11: ffffffffa698ca28 R12: ffff993c98823600
[ 41.316398] R13: ffff993c86311ebc R14: 0000000000000000 R15: 000000000000005c
[ 41.317700] FS: 00007fe13fc56740(0000) GS:ffff993cdd900000(0000) knlGS:0000000000000000
[ 41.319150] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 41.320152] CR2: 000000c00008a000 CR3: 0000000014908000 CR4: 0000000000350ee0
[ 41.321387] Call Trace:
[ 41.321819] <TASK>
[ 41.322193] skb_release_data+0x13f/0x1c0
[ 41.322902] __kfree_skb+0x20/0x30
[ 41.343870] tcp_recvmsg_locked+0x671/0x880
[ 41.363764] tcp_recvmsg+0x5e/0x1c0
[ 41.384102] inet_recvmsg+0x42/0x100
[ 41.406783] ? sock_recvmsg+0x1d/0x70
[ 41.428201] sock_read_iter+0x84/0xd0
[ 41.445592] ? 0xffffffffa3000000
[ 41.462442] new_sync_read+0x148/0x160
[ 41.479314] ? 0xffffffffa3000000
[ 41.496937] vfs_read+0x138/0x190
[ 41.517198] ksys_read+0x87/0xc0
[ 41.535336] do_syscall_64+0x3b/0x90
[ 41.551637] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 41.568050] RIP: 0033:0x48765b
[ 41.583955] Code: e8 4a 35 fe ff eb 88 cc cc cc cc cc cc cc cc e8 fb 7a fe ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30
[ 41.632818] RSP: 002b:000000c000a2f5b8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000
[ 41.664588] RAX: ffffffffffffffda RBX: 000000c000062000 RCX: 000000000048765b
[ 41.681205] RDX: 0000000000005e54 RSI: 000000c000e66000 RDI: 0000000000000016
[ 41.697164] RBP: 000000c000a2f608 R08: 0000000000000001 R09: 00000000000001b4
[ 41.713034] R10: 00000000000000b6 R11: 0000000000000212 R12: 00000000000000e9
[ 41.728755] R13: 0000000000000001 R14: 000000c000a92000 R15: ffffffffffffffff
[ 41.744254] </TASK>
[ 41.758585] Modules linked in: br_netfilter bridge veth netconsole virtio_net
and
[ 33.524802] BUG: Bad page state in process systemd-network pfn:11e60
[ 33.528617] page ffffe05dc0147b00 ffffe05dc04e7a00 ffff8ae9851ec000 (1) len 82 offset 252 metasize 4 hroom 0 hdr_len 12 data ffff8ae9851ec10c data_meta ffff8ae9851ec108 data_end ffff8ae9851ec14e
[ 33.529764] page:000000003792b5ba refcount:0 mapcount:-512 mapping:0000000000000000 index:0x0 pfn:0x11e60
[ 33.532463] flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff)
[ 33.532468] raw: 000fffffc0000000 0000000000000000 dead000000000122 0000000000000000
[ 33.532470] raw: 0000000000000000 0000000000000000 00000000fffffdff 0000000000000000
[ 33.532471] page dumped because: nonzero mapcount
[ 33.532472] Modules linked in: br_netfilter bridge veth netconsole virtio_net
[ 33.532479] CPU: 0 PID: 791 Comm: systemd-network Kdump: loaded Not tainted 5.18.0-rc1+ #37
[ 33.532482] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014
[ 33.532484] Call Trace:
[ 33.532496] <TASK>
[ 33.532500] dump_stack_lvl+0x45/0x5a
[ 33.532506] bad_page.cold+0x63/0x94
[ 33.532510] free_pcp_prepare+0x290/0x420
[ 33.532515] free_unref_page+0x1b/0x100
[ 33.532518] skb_release_data+0x13f/0x1c0
[ 33.532524] kfree_skb_reason+0x3e/0xc0
[ 33.532527] ip6_mc_input+0x23c/0x2b0
[ 33.532531] ip6_sublist_rcv_finish+0x83/0x90
[ 33.532534] ip6_sublist_rcv+0x22b/0x2b0
[3] XDP program to reproduce(xdp_pass.c):
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
SEC("xdp_pass")
int xdp_pkt_pass(struct xdp_md *ctx)
{
bpf_xdp_adjust_head(ctx, -(int)32);
return XDP_PASS;
}
char _license[] SEC("license") = "GPL";
compile: clang -O2 -g -Wall -target bpf -c xdp_pass.c -o xdp_pass.o
load on virtio_net: ip link set enp1s0 xdpdrv obj xdp_pass.o sec xdp_pass
CC: stable(a)vger.kernel.org
CC: Jason Wang <jasowang(a)redhat.com>
CC: Xuan Zhuo <xuanzhuo(a)linux.alibaba.com>
CC: Daniel Borkmann <daniel(a)iogearbox.net>
CC: "Michael S. Tsirkin" <mst(a)redhat.com>
CC: virtualization(a)lists.linux-foundation.org
Fixes: 8fb7da9e9907 ("virtio_net: get build_skb() buf by data ptr")
Signed-off-by: Nikolay Aleksandrov <razor(a)blackwall.org>
---
v3: Add a comment explaining why offset and headroom are equal,
no code changes
v2: Recalculate headroom based on data, data_hard_start and data_meta
drivers/net/virtio_net.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 87838cbe38cf..cbba9d2e8f32 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1005,6 +1005,24 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
* xdp.data_meta were adjusted
*/
len = xdp.data_end - xdp.data + vi->hdr_len + metasize;
+
+ /* recalculate headroom if xdp.data or xdp_data_meta
+ * were adjusted, note that offset should always point
+ * to the start of the reserved bytes for virtio_net
+ * header which are followed by xdp.data, that means
+ * that offset is equal to the headroom (when buf is
+ * starting at the beginning of the page, otherwise
+ * there is a base offset inside the page) but it's used
+ * with a different starting point (buf start) than
+ * xdp.data (buf start + vnet hdr size). If xdp.data or
+ * data_meta were adjusted by the xdp prog then the
+ * headroom size has changed and so has the offset, we
+ * can use data_hard_start, which points at buf start +
+ * vnet hdr size, to calculate the new headroom and use
+ * it later to compute buf start in page_to_skb()
+ */
+ headroom = xdp.data - xdp.data_hard_start - metasize;
+
/* We can only create skb based on xdp_page. */
if (unlikely(xdp_page != page)) {
rcu_read_unlock();
@@ -1012,7 +1030,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
head_skb = page_to_skb(vi, rq, xdp_page, offset,
len, PAGE_SIZE, false,
metasize,
- VIRTIO_XDP_HEADROOM);
+ headroom);
return head_skb;
}
break;
--
2.35.1
This is a note to let you know that I've just added the patch titled
usb: dwc3: gadget: Return proper request status
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
From c7428dbddcf4ea1919e1c8e15f715b94ca359268 Mon Sep 17 00:00:00 2001
From: Thinh Nguyen <Thinh.Nguyen(a)synopsys.com>
Date: Fri, 22 Apr 2022 17:36:28 -0700
Subject: usb: dwc3: gadget: Return proper request status
If the user sets the usb_request's no_interrupt, then there will be no
completion event for the request. Currently the driver incorrectly uses
the event status of a different request to report the status for a
request with no_interrupt. The dwc3 driver needs to check the TRB status
associated with the request when reporting its status.
Note: this is only applicable to missed_isoc TRB completion status, but
the other status are also listed for completeness/documentation.
Fixes: 6d8a019614f3 ("usb: dwc3: gadget: check for Missed Isoc from event status")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Thinh Nguyen <Thinh.Nguyen(a)synopsys.com>
Link: https://lore.kernel.org/r/db2c80108286cfd108adb05bad52138b78d7c3a7.16506736…
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/usb/dwc3/gadget.c | 31 ++++++++++++++++++++++++++++++-
1 file changed, 30 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index ab725d2262d6..0b9c2493844a 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -3274,6 +3274,7 @@ static int dwc3_gadget_ep_cleanup_completed_request(struct dwc3_ep *dep,
const struct dwc3_event_depevt *event,
struct dwc3_request *req, int status)
{
+ int request_status;
int ret;
if (req->request.num_mapped_sgs)
@@ -3294,7 +3295,35 @@ static int dwc3_gadget_ep_cleanup_completed_request(struct dwc3_ep *dep,
req->needs_extra_trb = false;
}
- dwc3_gadget_giveback(dep, req, status);
+ /*
+ * The event status only reflects the status of the TRB with IOC set.
+ * For the requests that don't set interrupt on completion, the driver
+ * needs to check and return the status of the completed TRBs associated
+ * with the request. Use the status of the last TRB of the request.
+ */
+ if (req->request.no_interrupt) {
+ struct dwc3_trb *trb;
+
+ trb = dwc3_ep_prev_trb(dep, dep->trb_dequeue);
+ switch (DWC3_TRB_SIZE_TRBSTS(trb->size)) {
+ case DWC3_TRBSTS_MISSED_ISOC:
+ /* Isoc endpoint only */
+ request_status = -EXDEV;
+ break;
+ case DWC3_TRB_STS_XFER_IN_PROG:
+ /* Applicable when End Transfer with ForceRM=0 */
+ case DWC3_TRBSTS_SETUP_PENDING:
+ /* Control endpoint only */
+ case DWC3_TRBSTS_OK:
+ default:
+ request_status = 0;
+ break;
+ }
+ } else {
+ request_status = status;
+ }
+
+ dwc3_gadget_giveback(dep, req, request_status);
out:
return ret;
--
2.36.0
--
Hello,
My name is Warren E. Buffett, an American business magnate, investor
and philanthropist. I am the most successful investor in the world. I
believe strongly in giving while living' I had one idea that never
changed in my mind ? That you should use your wealth to help people
and I have decided to give you $2,500,000.00 to randomly selected
individuals worldwide. You should count yourself as the lucky
individual. Kindly reply back so I know your email address is valid.
God bless you.
Mr. Warren E. Buffett
All creation paths except for O_TMPFILE handle umask in the vfs directly
if the filesystem doesn't support or enable POSIX ACLs. If the filesystem
does then umask handling is deferred until posix_acl_create().
Because, O_TMPFILE misses umask handling in the vfs it will not honor
umask settings. Fix this by adding the missing umask handling.
Fixes: 60545d0d4610 ("[O_TMPFILE] it's still short a few helpers, but infrastructure should be OK now...")
Cc: <stable(a)vger.kernel.org> # 4.19+
Reported-by: Christian Brauner (Microsoft) <brauner(a)kernel.org>
Acked-by: Christian Brauner (Microsoft) <brauner(a)kernel.org>
Reviewed-by: Darrick J. Wong <djwong(a)kernel.org>
Signed-off-by: Yang Xu <xuyang2018.jy(a)fujitsu.com>
---
fs/namei.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/namei.c b/fs/namei.c
index 509657fdf4f5..73646e28fae0 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3521,6 +3521,8 @@ struct dentry *vfs_tmpfile(struct user_namespace *mnt_userns,
child = d_alloc(dentry, &slash_name);
if (unlikely(!child))
goto out_err;
+ if (!IS_POSIXACL(dir))
+ mode &= ~current_umask();
error = dir->i_op->tmpfile(mnt_userns, dir, child, mode);
if (error)
goto out_err;
--
2.27.0
In qla2x00_probe_one() -> qla2x00_mem_alloc(), fields in variable ha
is allocated and initialized. Fields ha->loop_id_map and ha->npiv_info
are also allocated in this function, but are freed when the function
encounters an error. Function qla2x00_probe_one() then calls
qla2x00_mem_free() to handle the error, which frees the corresponding
fields again. This results in double free of ha->loop_id_map and ha->
npiv_info, since the fields are not NULLed after freed the first time.
Fix this by storing NULL to the corresponding fields inside
qla2x00_mem_alloc() error handlers.
Fixes: e4e3a2ce9556 ("scsi: qla2xxx: Add ability to autodetect SFP type")
Fixes: b64b0e8fd964 ("[SCSI] qla2xxx: Pass in optional extended-initialization control block.")
Cc: stable(a)vger.kernel.org
Signed-off-by: Keita Suzuki <keitasuzuki.park(a)sslab.ics.keio.ac.jp>
---
drivers/scsi/qla2xxx/qla_os.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 762229d495a8..a0b40578dbc8 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -4396,6 +4396,7 @@ qla2x00_mem_alloc(struct qla_hw_data *ha, uint16_t req_len, uint16_t rsp_len,
ha->sfp_data, ha->sfp_data_dma);
fail_sfp_data:
kfree(ha->loop_id_map);
+ ha->loop_id_map = NULL;
fail_loop_id_map:
dma_pool_free(ha->s_dma_pool, ha->async_pd, ha->async_pd_dma);
fail_async_pd:
@@ -4404,6 +4405,7 @@ qla2x00_mem_alloc(struct qla_hw_data *ha, uint16_t req_len, uint16_t rsp_len,
dma_pool_free(ha->s_dma_pool, ha->ex_init_cb, ha->ex_init_cb_dma);
fail_ex_init_cb:
kfree(ha->npiv_info);
+ ha->npiv_info = NULL;
fail_npiv_info:
dma_free_coherent(&ha->pdev->dev, ((*rsp)->length + 1) *
sizeof(response_t), (*rsp)->ring, (*rsp)->dma);
--
2.25.1