From: Thinh Tran thinhtr@linux.ibm.com
[ Upstream commit d27e2da94a42655861ca4baea30c8cd65546f25d ]
Fix race condition leading to system crash during EEH error handling
During EEH error recovery, the bnx2x driver's transmit timeout logic could cause a race condition when handling reset tasks. The bnx2x_tx_timeout() schedules reset tasks via bnx2x_sp_rtnl_task(), which ultimately leads to bnx2x_nic_unload(). In bnx2x_nic_unload() SGEs are freed using bnx2x_free_rx_sge_range(). However, this could overlap with the EEH driver's attempt to reset the device using bnx2x_io_slot_reset(), which also tries to free SGEs. This race condition can result in system crashes due to accessing freed memory locations in bnx2x_free_rx_sge()
799 static inline void bnx2x_free_rx_sge(struct bnx2x *bp, 800 struct bnx2x_fastpath *fp, u16 index) 801 { 802 struct sw_rx_page *sw_buf = &fp->rx_page_ring[index]; 803 struct page *page = sw_buf->page; .... where sw_buf was set to NULL after the call to dma_unmap_page() by the preceding thread.
EEH: Beginning: 'slot_reset' PCI 0011:01:00.0#10000: EEH: Invoking bnx2x->slot_reset() bnx2x: [bnx2x_io_slot_reset:14228(eth1)]IO slot reset initializing... bnx2x 0011:01:00.0: enabling device (0140 -> 0142) bnx2x: [bnx2x_io_slot_reset:14244(eth1)]IO slot reset --> driver unload Kernel attempted to read user page (0) - exploit attempt? (uid: 0) BUG: Kernel NULL pointer dereference on read at 0x00000000 Faulting instruction address: 0xc0080000025065fc Oops: Kernel access of bad area, sig: 11 [#1] ..... Call Trace: [c000000003c67a20] [c00800000250658c] bnx2x_io_slot_reset+0x204/0x610 [bnx2x] (unreliable) [c000000003c67af0] [c0000000000518a8] eeh_report_reset+0xb8/0xf0 [c000000003c67b60] [c000000000052130] eeh_pe_report+0x180/0x550 [c000000003c67c70] [c00000000005318c] eeh_handle_normal_event+0x84c/0xa60 [c000000003c67d50] [c000000000053a84] eeh_event_handler+0xf4/0x170 [c000000003c67da0] [c000000000194c58] kthread+0x1c8/0x1d0 [c000000003c67e10] [c00000000000cf64] ret_from_kernel_thread+0x5c/0x64
To solve this issue, we need to verify page pool allocations before freeing.
Fixes: 4cace675d687 ("bnx2x: Alloc 4k fragment for each rx ring buffer element") Signed-off-by: Thinh Tran thinhtr@linux.ibm.com Reviewed-by: Jiri Pirko jiri@nvidia.com Link: https://lore.kernel.org/r/20240315205535.1321-1-thinhtr@linux.ibm.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h index df5e8c2e8eafe..844195849ae76 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h @@ -1008,9 +1008,6 @@ static inline void bnx2x_set_fw_mac_addr(__le16 *fw_hi, __le16 *fw_mid, static inline void bnx2x_free_rx_mem_pool(struct bnx2x *bp, struct bnx2x_alloc_pool *pool) { - if (!pool->page) - return; - put_page(pool->page);
pool->page = NULL; @@ -1021,6 +1018,9 @@ static inline void bnx2x_free_rx_sge_range(struct bnx2x *bp, { int i;
+ if (!fp->page_pool.page) + return; + if (fp->mode == TPA_MODE_DISABLED) return;