diff options
| author | Liu Song <liu.song13@zte.com.cn> | 2025-07-10 14:38:45 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-02-16 10:13:34 +0100 |
| commit | 73cee890adafa2c219bb865356e08e7f82423fe5 (patch) | |
| tree | c156e50dbeebad063ab0bf894ce6e8115df117f9 | |
| parent | 0cd2c155740dbd00868ac5a8ae5d14cd6b9ed385 (diff) | |
PCI: endpoint: Avoid creating sub-groups asynchronously
commit 7c5c7d06bd1f86d2c3ebe62be903a4ba42db4d2c upstream.
The asynchronous creation of sub-groups by a delayed work could lead to a
NULL pointer dereference when the driver directory is removed before the
work completes.
The crash can be easily reproduced with the following commands:
# cd /sys/kernel/config/pci_ep/functions/pci_epf_test
# for i in {1..20}; do mkdir test && rmdir test; done
BUG: kernel NULL pointer dereference, address: 0000000000000088
...
Call Trace:
configfs_register_group+0x3d/0x190
pci_epf_cfs_work+0x41/0x110
process_one_work+0x18f/0x350
worker_thread+0x25a/0x3a0
Fix this issue by using configfs_add_default_group() API which does not
have the deadlock problem as configfs_register_group() and does not require
the delayed work handler.
Fixes: e85a2d783762 ("PCI: endpoint: Add support in configfs to associate two EPCs with EPF")
Signed-off-by: Liu Song <liu.song13@zte.com.cn>
[mani: slightly reworded the description and added stable list]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@kernel.org
Link: https://patch.msgid.link/20250710143845409gLM6JdlwPhlHG9iX3F6jK@zte.com.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/pci/endpoint/pci-ep-cfs.c | 15 |
1 files changed, 5 insertions, 10 deletions
diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c index ef50c82e647f..43feb6139fa3 100644 --- a/drivers/pci/endpoint/pci-ep-cfs.c +++ b/drivers/pci/endpoint/pci-ep-cfs.c @@ -23,7 +23,6 @@ struct pci_epf_group { struct config_group group; struct config_group primary_epc_group; struct config_group secondary_epc_group; - struct delayed_work cfs_work; struct pci_epf *epf; int index; }; @@ -103,7 +102,7 @@ static struct config_group secondary_epc_group = &epf_group->secondary_epc_group; config_group_init_type_name(secondary_epc_group, "secondary", &pci_secondary_epc_type); - configfs_register_group(&epf_group->group, secondary_epc_group); + configfs_add_default_group(secondary_epc_group, &epf_group->group); return secondary_epc_group; } @@ -166,7 +165,7 @@ static struct config_group config_group_init_type_name(primary_epc_group, "primary", &pci_primary_epc_type); - configfs_register_group(&epf_group->group, primary_epc_group); + configfs_add_default_group(primary_epc_group, &epf_group->group); return primary_epc_group; } @@ -570,15 +569,13 @@ static void pci_ep_cfs_add_type_group(struct pci_epf_group *epf_group) return; } - configfs_register_group(&epf_group->group, group); + configfs_add_default_group(group, &epf_group->group); } -static void pci_epf_cfs_work(struct work_struct *work) +static void pci_epf_cfs_add_sub_groups(struct pci_epf_group *epf_group) { - struct pci_epf_group *epf_group; struct config_group *group; - epf_group = container_of(work, struct pci_epf_group, cfs_work.work); group = pci_ep_cfs_add_primary_group(epf_group); if (IS_ERR(group)) { pr_err("failed to create 'primary' EPC interface\n"); @@ -637,9 +634,7 @@ static struct config_group *pci_epf_make(struct config_group *group, kfree(epf_name); - INIT_DELAYED_WORK(&epf_group->cfs_work, pci_epf_cfs_work); - queue_delayed_work(system_wq, &epf_group->cfs_work, - msecs_to_jiffies(1)); + pci_epf_cfs_add_sub_groups(epf_group); return &epf_group->group; |