TPA IDs are generated by FW and can be up to 1024. bnxt_alloc_agg_idx is intended to wrap the FW ID down to a software ID which is used to index rxr->rx_tpa, and to generate a mapping between FW IDs and the wrapped software ID. On a 57608 with firmware version 233, the firmware advertises 32 concurrent TPAs. As of the commit under fixes, bp->max_tpa on this NIC is set to 32. If the software ID from bnxt_alloc_agg_idx is above 31, this results in an invalid address being loaded on this line: tpa_info = &rxr->rx_tpa[agg_id]; because rx_tpa is allocated with only bp->max_tpa (32) entries. Writes to tpa_info later in the code are out of bounds. This bug results in a crash at boot: Oops: general protection fault, kernel NULL pointer dereference 0x8: 0000 [#1] SMP NOPTI RIP: 0010:bnxt_rx_pkt+0xc0/0x1560 RSP: 0018:ffffc900009b8c78 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000048 RCX: 0000000206682516 RDX: ffffc900009b8db4 RSI: 0000000000000000 RDI: 01ffffff038fe1c0 RBP: ffffc9006e687480 R08: ffffc9006e687000 R09: 0000000000003048 R10: 0000000000000480 R11: ffff8881c6083900 R12: 0000000006682516 R13: ffff8881c6095400 R14: 0000000000000016 R15: ffff8881c6b66680 FS: 0000000000000000(0000) GS:ffff88fef3c77000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc8bda40584 CR3: 000000807c812001 CR4: 0000000008772ef0 PKRU: 55555554 Call Trace: ? __netif_receive_skb_list_core+0x1ca/0x250 __bnxt_poll_work+0x152/0x280 bnxt_poll_p5+0x1cd/0x480 __napi_poll+0x30/0x180 net_rx_action+0x20b/0x3b0 ? note_gp_changes+0x53/0xe0 ? tick_setup_sched_timer+0x180/0x180 ? __napi_schedule+0x9a/0xb0 ? bnxt_msix+0x24/0x30 handle_softirqs+0xdd/0x2c0 __irq_exit_rcu.llvm.3171231171502365008+0x47/0xf0 common_interrupt+0x85/0x90 asm_common_interrupt+0x22/0x40 This stack trace is from a crash triggered when an out of bounds rx_tpa is dereferenced. The invalid write mentioned above is silent in this particular crash. Fix this by allocating rx_tpa with bp->max_tpa rounded up to the next power of 2 (bp->max_tpa_roundup_size) entries and masking the FW TPA ID with that size, so the wrapped ID can never index past the end of the array. Fixes: 54c28fab2fa5 ("bnxt_en: Set bp->max_tpa according to what the FW supports") Reported-by: Raphael Cardoso Fernandes Suggested-by: Michael Chan Cc: stable@vger.kernel.org Signed-off-by: Joe Damato --- v4: - Moved bp->max_tpa_roundup_size init out of the early return path and documented that TPA is unsupported there, as suggested by Michael. v3: https://lore.kernel.org/netdev/20260827185700.2157164-1-joe@dama.to/ - Addressed an issue Sashiko pointed out, where max_tpa_roundup_size may be left unset if bnxt_alloc_tpa_info returns early, which would lead to out of bounds access. - The other pre-existing issues Sashiko pointed out are unrelated to this patch and would need different Fixes tags, so they are better served with separate patches in the future. v2: https://lore.kernel.org/netdev/20260825001842.2501798-1-joe@dama.to/ - Followed Michael's suggestion on the v1 to increase the size of the tpa array so that wrapping indexes into the array is a simple mask. - Add Suggested-by because the approach was suggested by Michael. - Add a Reported-by so that Raphael gets credit for reporting this bug. - Boot tested on a machine with a 57608 and the crash did not reproduce. v1: https://lore.kernel.org/netdev/20260821233549.3134699-1-joe@dama.to/ drivers/net/ethernet/broadcom/bnxt/bnxt.c | 28 +++++++++++++++-------- drivers/net/ethernet/broadcom/bnxt/bnxt.h | 2 +- 2 files changed, 19 insertions(+), 11 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index d59bcca73a2b..bee54cc86996 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -1514,14 +1514,16 @@ static int bnxt_discard_rx(struct bnxt *bp, struct bnxt_cp_ring_info *cpr, return 0; } -static u16 bnxt_alloc_agg_idx(struct bnxt_rx_ring_info *rxr, u16 agg_id) +static u16 bnxt_alloc_agg_idx(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, + u16 agg_id) { struct bnxt_tpa_idx_map *map = rxr->rx_tpa_idx_map; - u16 idx = agg_id & MAX_TPA_P5_MASK; + u16 idx = agg_id & (bp->max_tpa_roundup_size - 1); if (test_bit(idx, map->agg_idx_bmap)) { - idx = find_first_zero_bit(map->agg_idx_bmap, MAX_TPA_P5); - if (idx >= MAX_TPA_P5) + idx = find_first_zero_bit(map->agg_idx_bmap, + bp->max_tpa_roundup_size); + if (idx >= bp->max_tpa_roundup_size) return INVALID_HW_RING_ID; } __set_bit(idx, map->agg_idx_bmap); @@ -1586,7 +1588,7 @@ static void bnxt_tpa_start(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, if (bp->flags & BNXT_FLAG_CHIP_P5_PLUS) { agg_id = TPA_START_AGG_ID_P5(tpa_start); - agg_id = bnxt_alloc_agg_idx(rxr, agg_id); + agg_id = bnxt_alloc_agg_idx(bp, rxr, agg_id); if (unlikely(agg_id == INVALID_HW_RING_ID)) { netdev_warn(bp->dev, "Unable to allocate agg ID for ring %d, agg 0x%x\n", rxr->bnapi->index, @@ -3584,7 +3586,7 @@ static void bnxt_free_one_tpa_info_data(struct bnxt *bp, { int i; - for (i = 0; i < bp->max_tpa; i++) { + for (i = 0; i < bp->max_tpa_roundup_size; i++) { struct bnxt_tpa_info *tpa_info = &rxr->rx_tpa[i]; u8 *data = tpa_info->data; @@ -3781,7 +3783,7 @@ static void bnxt_free_one_tpa_info(struct bnxt *bp, kfree(rxr->rx_tpa_idx_map); rxr->rx_tpa_idx_map = NULL; if (rxr->rx_tpa) { - for (i = 0; i < bp->max_tpa; i++) { + for (i = 0; i < bp->max_tpa_roundup_size; i++) { kfree(rxr->rx_tpa[i].agg_arr); rxr->rx_tpa[i].agg_arr = NULL; } @@ -3807,13 +3809,14 @@ static int bnxt_alloc_one_tpa_info(struct bnxt *bp, struct rx_agg_cmp *agg; int i; - rxr->rx_tpa = kzalloc_objs(struct bnxt_tpa_info, bp->max_tpa); + rxr->rx_tpa = kzalloc_objs(struct bnxt_tpa_info, + bp->max_tpa_roundup_size); if (!rxr->rx_tpa) return -ENOMEM; if (!(bp->flags & BNXT_FLAG_CHIP_P5_PLUS)) return 0; - for (i = 0; i < bp->max_tpa; i++) { + for (i = 0; i < bp->max_tpa_roundup_size; i++) { agg = kzalloc_objs(*agg, MAX_SKB_FRAGS); if (!agg) return -ENOMEM; @@ -3832,6 +3835,10 @@ static int bnxt_alloc_tpa_info(struct bnxt *bp) bp->max_tpa = MAX_TPA; if (bp->flags & BNXT_FLAG_CHIP_P5_PLUS) { + /* TPA is not supported at all, so there is nothing to + * allocate. BNXT_SUPPORTS_TPA() is false in this case and + * neither LRO nor HW GRO can be enabled. + */ if (!bp->max_tpa_v2) return 0; bp->max_tpa = min_t(u16, bp->max_tpa_v2, MAX_TPA_P5); @@ -3839,6 +3846,7 @@ static int bnxt_alloc_tpa_info(struct bnxt *bp) if (bp->max_tpa <= 32 && BNXT_CHIP_P5(bp) && !BNXT_NPAR(bp)) bp->max_tpa = MAX_TPA_P5; } + bp->max_tpa_roundup_size = roundup_pow_of_two(bp->max_tpa); for (i = 0; i < bp->rx_nr_rings; i++) { struct bnxt_rx_ring_info *rxr = &bp->rx_ring[i]; @@ -4551,7 +4559,7 @@ static int bnxt_alloc_one_tpa_info_data(struct bnxt *bp, u8 *data; int i; - for (i = 0; i < bp->max_tpa; i++) { + for (i = 0; i < bp->max_tpa_roundup_size; i++) { data = __bnxt_alloc_rx_frag(bp, &mapping, rxr, GFP_KERNEL); if (!data) diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h index ab894f8addef..de46b42d7c98 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h @@ -789,7 +789,6 @@ struct nqe_cn { #define MAX_TPA 64 #define MAX_TPA_P5 256 -#define MAX_TPA_P5_MASK (MAX_TPA_P5 - 1) #define MAX_TPA_SEGS_P5 0x3f #if (BNXT_PAGE_SHIFT == 16) @@ -2380,6 +2379,7 @@ struct bnxt { u16 max_tpa_v2; u16 max_tpa; + u16 max_tpa_roundup_size; u32 rx_buf_size; u32 rx_buf_use_size; /* useable size */ u16 rx_offset; base-commit: e2a6641e3bfde58f2284f9859c2b0fdcc6d1c0da -- 2.53.0-Meta