4.19-stable review patch. If anyone has any objections, please let me know.
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From: Gustavo A. R. Silva gustavoars@kernel.org
commit eea03d18af9c44235865a4bc9bec4d780ef6cf21 upstream.
The flexible structure (a structure that contains a flexible-array member at the end) `qed_ll2_tx_packet` is nested within the second layer of `struct qed_ll2_info`:
struct qed_ll2_tx_packet { ... /* Flexible Array of bds_set determined by max_bds_per_packet */ struct { struct core_tx_bd *txq_bd; dma_addr_t tx_frag; u16 frag_len; } bds_set[]; };
struct qed_ll2_tx_queue { ... struct qed_ll2_tx_packet cur_completing_packet; };
struct qed_ll2_info { ... struct qed_ll2_tx_queue tx_queue; struct qed_ll2_cbs cbs; };
The problem is that member `cbs` in `struct qed_ll2_info` is placed just after an object of type `struct qed_ll2_tx_queue`, which is in itself an implicit flexible structure, which by definition ends in a flexible array member, in this case `bds_set`. This causes an undefined behavior bug at run-time when dynamic memory is allocated for `bds_set`, which could lead to a serious issue if `cbs` in `struct qed_ll2_info` is overwritten by the contents of `bds_set`. Notice that the type of `cbs` is a structure full of function pointers (and a cookie :) ):
include/linux/qed/qed_ll2_if.h: 107 typedef 108 void (*qed_ll2_complete_rx_packet_cb)(void *cxt, 109 struct qed_ll2_comp_rx_data *data); 110 111 typedef 112 void (*qed_ll2_release_rx_packet_cb)(void *cxt, 113 u8 connection_handle, 114 void *cookie, 115 dma_addr_t rx_buf_addr, 116 bool b_last_packet); 117 118 typedef 119 void (*qed_ll2_complete_tx_packet_cb)(void *cxt, 120 u8 connection_handle, 121 void *cookie, 122 dma_addr_t first_frag_addr, 123 bool b_last_fragment, 124 bool b_last_packet); 125 126 typedef 127 void (*qed_ll2_release_tx_packet_cb)(void *cxt, 128 u8 connection_handle, 129 void *cookie, 130 dma_addr_t first_frag_addr, 131 bool b_last_fragment, bool b_last_packet); 132 133 typedef 134 void (*qed_ll2_slowpath_cb)(void *cxt, u8 connection_handle, 135 u32 opaque_data_0, u32 opaque_data_1); 136 137 struct qed_ll2_cbs { 138 qed_ll2_complete_rx_packet_cb rx_comp_cb; 139 qed_ll2_release_rx_packet_cb rx_release_cb; 140 qed_ll2_complete_tx_packet_cb tx_comp_cb; 141 qed_ll2_release_tx_packet_cb tx_release_cb; 142 qed_ll2_slowpath_cb slowpath_cb; 143 void *cookie; 144 };
Fix this by moving the declaration of `cbs` to the middle of its containing structure `qed_ll2_info`, preventing it from being overwritten by the contents of `bds_set` at run-time.
This bug was introduced in 2017, when `bds_set` was converted to a one-element array, and started to be used as a Variable Length Object (VLO) at run-time.
Fixes: f5823fe6897c ("qed: Add ll2 option to limit the number of bds per packet") Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva gustavoars@kernel.org Reviewed-by: Kees Cook keescook@chromium.org Reviewed-by: Simon Horman horms@kernel.org Link: https://lore.kernel.org/r/ZQ+Nz8DfPg56pIzr@work Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/qlogic/qed/qed_ll2.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/net/ethernet/qlogic/qed/qed_ll2.h +++ b/drivers/net/ethernet/qlogic/qed/qed_ll2.h @@ -122,9 +122,9 @@ struct qed_ll2_info { enum core_tx_dest tx_dest; u8 tx_stats_en; bool main_func_queue; + struct qed_ll2_cbs cbs; struct qed_ll2_rx_queue rx_queue; struct qed_ll2_tx_queue tx_queue; - struct qed_ll2_cbs cbs; };
/**