{"id":"DEBIAN-CVE-2022-48744","details":"In the Linux kernel, the following vulnerability has been resolved:  net/mlx5e: Avoid field-overflowing memcpy()  In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memcpy(), memmove(), and memset(), avoid intentionally writing across neighboring fields.  Use flexible arrays instead of zero-element arrays (which look like they are always overflowing) and split the cross-field memcpy() into two halves that can be appropriately bounds-checked by the compiler.  We were doing:  \t#define ETH_HLEN  14 \t#define VLAN_HLEN  4 \t... \t#define MLX5E_XDP_MIN_INLINE (ETH_HLEN + VLAN_HLEN) \t...         struct mlx5e_tx_wqe      *wqe  = mlx5_wq_cyc_get_wqe(wq, pi); \t...         struct mlx5_wqe_eth_seg  *eseg = &wqe-\u003eeth;         struct mlx5_wqe_data_seg *dseg = wqe-\u003edata; \t... \tmemcpy(eseg-\u003einline_hdr.start, xdptxd-\u003edata, MLX5E_XDP_MIN_INLINE);  target is wqe-\u003eeth.inline_hdr.start (which the compiler sees as being 2 bytes in size), but copying 18, intending to write across start (really vlan_tci, 2 bytes). The remaining 16 bytes get written into wqe-\u003edata[0], covering byte_count (4 bytes), lkey (4 bytes), and addr (8 bytes).  struct mlx5e_tx_wqe {         struct mlx5_wqe_ctrl_seg   ctrl;                 /*     0    16 */         struct mlx5_wqe_eth_seg    eth;                  /*    16    16 */         struct mlx5_wqe_data_seg   data[];               /*    32     0 */          /* size: 32, cachelines: 1, members: 3 */         /* last cacheline: 32 bytes */ };  struct mlx5_wqe_eth_seg {         u8                         swp_outer_l4_offset;  /*     0     1 */         u8                         swp_outer_l3_offset;  /*     1     1 */         u8                         swp_inner_l4_offset;  /*     2     1 */         u8                         swp_inner_l3_offset;  /*     3     1 */         u8                         cs_flags;             /*     4     1 */         u8                         swp_flags;            /*     5     1 */         __be16                     mss;                  /*     6     2 */         __be32                     flow_table_metadata;  /*     8     4 */         union {                 struct {                         __be16     sz;                   /*    12     2 */                         u8         start[2];             /*    14     2 */                 } inline_hdr;                            /*    12     4 */                 struct {                         __be16     type;                 /*    12     2 */                         __be16     vlan_tci;             /*    14     2 */                 } insert;                                /*    12     4 */                 __be32             trailer;              /*    12     4 */         };                                               /*    12     4 */          /* size: 16, cachelines: 1, members: 9 */         /* last cacheline: 16 bytes */ };  struct mlx5_wqe_data_seg {         __be32                     byte_count;           /*     0     4 */         __be32                     lkey;                 /*     4     4 */         __be64                     addr;                 /*     8     8 */          /* size: 16, cachelines: 1, members: 3 */         /* last cacheline: 16 bytes */ };  So, split the memcpy() so the compiler can reason about the buffer sizes.  \"pahole\" shows no size nor member offset changes to struct mlx5e_tx_wqe nor struct mlx5e_umr_wqe. \"objdump -d\" shows no meaningful object code changes (i.e. only source line number induced differences and optimizations).","modified":"2026-09-01T16:05:29.209451932Z","published":"2024-06-20T12:15:12.700Z","upstream":["CVE-2022-48744"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2022-48744"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.16.7-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-48744.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.16.7-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-48744.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.16.7-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-48744.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}