CVE-2026-31546 — linux / linux_kernel
NULL Pointer DereferenceIn the Linux kernel, the following vulnerability has been resolved:
net: bonding: fix NULL deref in bond_debug_rlb_hash_show
rlb_clear_slave intentionally keeps RLB hash-table entries on the rx_hashtbl_used_head list with slave set to NULL when no replacement slave is available. However, bond_debug_rlb_hash_show visites client_info->slave without checking if it's NULL.
Other used-list iterators in bond_alb.c already handle this NULL-slave state safely:
- rlb_update_client returns early on !client_info->slave
- rlb_req_update_slave_clients, rlb_clear_slave, and rlb_rebalance compare slave values before visiting
- lb_req_update_subnet_clients continues if slave is NULL
The following NULL deref crash can be trigger in bond_debug_rlb_hash_show:
[ 1.289791] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 1.292058] RIP: 0010:bond_debug_rlb_hash_show (drivers/net/bonding/bond_debugfs.c:41) [ 1.293101] RSP: 0018:ffffc900004a7d00 EFLAGS: 00010286 [ 1.293333] RAX: 0000000000000000 RBX: ffff888102b48200 RCX: ffff888102b48204 [ 1.293631] RDX: ffff888102b48200 RSI: ffffffff839daad5 RDI: ffff888102815078 [ 1.293924] RBP: ffff888102815078 R08: ffff888102b4820e R09: 0000000000000000 [ 1.294267] R10: 0000000000000000 R11: 0000000000000000 R12: ffff888100f929c0 [ 1.294564] R13: ffff888100f92a00 R14: 0000000000000001 R15: ffffc900004a7ed8 [ 1.294864] FS: 0000000001395380(0000) GS:ffff888196e75000(0000) knlGS:0000000000000000 [ 1.295239] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1.295480] CR2: 0000000000000000 CR3: 0000000102adc004 CR4: 0000000000772ef0 [ 1.295897] Call Trace: [ 1.296134] seq_read_iter (fs/seq_file.c:231) [ 1.296341] seq_read (fs/seq_file.c:164) [ 1.296493] full_proxy_read (fs/debugfs/file.c:378 (discriminator 1)) [ 1.296658] vfs_read (fs/read_write.c:572) [ 1.296981] ksys_read (fs/read_write.c:717) [ 1.297132] do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) [ 1.297325] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
Add a NULL check and print "(none)" for entries with no assigned slave.
| Software | From | Fixed in |
|---|---|---|
| linux / linux_kernel | 2.6.38.1 | 5.10.253 |
| linux / linux_kernel | 5.11 | 5.15.203 |
| linux / linux_kernel | 5.16 | 6.1.167 |
| linux / linux_kernel | 6.2 | 6.6.130 |
| linux / linux_kernel | 6.7 | 6.12.78 |
| linux / linux_kernel | 6.13 | 6.18.20 |
| linux / linux_kernel | 6.19 | 6.19.10 |
| linux / linux_kernel | 2.6.38 | 2.6.38.x |
| linux / linux_kernel | 7.0-rc1 | 7.0-rc1.x |
| linux / linux_kernel | 7.0-rc2 | 7.0-rc2.x |
| linux / linux_kernel | 7.0-rc3 | 7.0-rc3.x |
| linux / linux_kernel | 7.0-rc4 | 7.0-rc4.x |
| linux / linux_kernel | 7.0-rc5 | 7.0-rc5.x |
| linux / linux_kernel | 7.0-rc6 | 7.0-rc6.x |
| linux / linux_kernel | 7.0-rc7 | 7.0-rc7.x |
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://git.kernel.org/stable/c/017d674cf6930e9586a29ee808c7ca09d1396d07
- https://git.kernel.org/stable/c/0a3f8cd3f370247ded14d38d216b49dd30eade76
- https://git.kernel.org/stable/c/19f0fd87df0e5746b24f5caa465a66a8c6e6e241
- https://git.kernel.org/stable/c/2ec2c777f357a83c3d503d8d9370c90b60f0ae63
- https://git.kernel.org/stable/c/605b52497bf89b3b154674deb135da98f916e390
- https://git.kernel.org/stable/c/6a3bb74e25d79cbb15f67ef80f71e2b2bfe27ff4
- https://git.kernel.org/stable/c/ec9762f0df2f9fbe3f40a3bfa8aab8b2f721466c
- https://git.kernel.org/stable/c/edacf1613f7b26423ebfa8b2892e7453c4235354
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