CVE-2022-49592 in Linux
Summary
by MITRE • 02/26/2025
In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: fix dma queue left shift overflow issue
When queue number is > 4, left shift overflows due to 32 bits integer variable. Mask calculation is wrong for MTL_RXQ_DMA_MAP1.
If CONFIG_UBSAN is enabled, kernel dumps below warning: [ 10.363842] ==================================================================
[ 10.363882] UBSAN: shift-out-of-bounds in /build/linux-intel-iotg-5.15-8e6Tf4/
linux-intel-iotg-5.15-5.15.0/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c:224:12 [ 10.363929] shift exponent 40 is too large for 32-bit type 'unsigned int'
[ 10.363953] CPU: 1 PID: 599 Comm: NetworkManager Not tainted 5.15.0-1003-intel-iotg
[ 10.363956] Hardware name: ADLINK Technology Inc. LEC-EL/LEC-EL, BIOS 0.15.11 12/22/2021
[ 10.363958] Call Trace:
[ 10.363960]
[ 10.363963] dump_stack_lvl+0x4a/0x5f
[ 10.363971] dump_stack+0x10/0x12
[ 10.363974] ubsan_epilogue+0x9/0x45
[ 10.363976] __ubsan_handle_shift_out_of_bounds.cold+0x61/0x10e
[ 10.363979] ? wake_up_klogd+0x4a/0x50
[ 10.363983] ? vprintk_emit+0x8f/0x240
[ 10.363986] dwmac4_map_mtl_dma.cold+0x42/0x91 [stmmac]
[ 10.364001] stmmac_mtl_configuration+0x1ce/0x7a0 [stmmac]
[ 10.364009] ? dwmac410_dma_init_channel+0x70/0x70 [stmmac]
[ 10.364020] stmmac_hw_setup.cold+0xf/0xb14 [stmmac]
[ 10.364030] ? page_pool_alloc_pages+0x4d/0x70
[ 10.364034] ? stmmac_clear_tx_descriptors+0x6e/0xe0 [stmmac]
[ 10.364042] stmmac_open+0x39e/0x920 [stmmac]
[ 10.364050] __dev_open+0xf0/0x1a0
[ 10.364054] __dev_change_flags+0x188/0x1f0
[ 10.364057] dev_change_flags+0x26/0x60
[ 10.364059] do_setlink+0x908/0xc40
[ 10.364062] ? do_setlink+0xb10/0xc40
[ 10.364064] ? __nla_validate_parse+0x4c/0x1a0
[ 10.364068] __rtnl_newlink+0x597/0xa10
[ 10.364072] ? __nla_reserve+0x41/0x50
[ 10.364074] ? __kmalloc_node_track_caller+0x1d0/0x4d0
[ 10.364079] ? pskb_expand_head+0x75/0x310
[ 10.364082] ? nla_reserve_64bit+0x21/0x40
[ 10.364086] ? skb_free_head+0x65/0x80
[ 10.364089] ? security_sock_rcv_skb+0x2c/0x50
[ 10.364094] ? __cond_resched+0x19/0x30
[ 10.364097] ? kmem_cache_alloc_trace+0x15a/0x420
[ 10.364100] rtnl_newlink+0x49/0x70
This change fixes MTL_RXQ_DMA_MAP1 mask issue and channel/queue mapping warning.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=216195
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Analysis
by VulDB Data Team • 10/23/2025
The vulnerability described in CVE-2022-49592 represents a critical integer overflow issue within the Linux kernel's stmmac network driver implementation. This flaw manifests specifically in the dwmac4_core.c file where a 32-bit unsigned integer variable is subjected to a left shift operation that exceeds the maximum representable value for that data type. The issue occurs when the queue number exceeds four, triggering a shift-out-of-bounds condition that violates fundamental integer arithmetic constraints. The vulnerability is particularly concerning as it can be triggered through normal network interface configuration operations, making it exploitable in both legitimate and malicious contexts.
The technical root cause stems from improper mask calculation logic within the MTL_RXQ_DMA_MAP1 register configuration mechanism. When the system attempts to map DMA channels to receive queues beyond the fourth queue, the left shift operation generates a value that exceeds the 32-bit unsigned integer capacity, resulting in undefined behavior and potential kernel panic conditions. This specific violation aligns with CWE-191, which addresses integer underflow and overflow conditions, and more broadly with CWE-190, which covers integer overflow and underflow vulnerabilities. The Universal Sanitizer (UBSAN) framework correctly identifies this issue by detecting that the shift exponent value of 40 exceeds the 32-bit type's capacity, generating the detailed error trace that demonstrates the vulnerability's path through the kernel's network stack.
The operational impact of this vulnerability extends beyond simple functional failures to potentially compromise system stability and availability. When CONFIG_UBSAN is enabled, the kernel generates explicit warnings that can indicate system instability, and in severe cases may lead to kernel oops or system crashes during network interface initialization or configuration changes. The attack surface includes any system utilizing the stmmac network driver with more than four DMA queues, particularly affecting embedded systems and IoT devices that rely on the Intel IoTG kernel variant. This vulnerability directly impacts the STMMAC driver's ability to properly configure hardware resources, potentially leading to complete network interface failure and disruption of network services. The specific call trace shows the vulnerability propagates through the network management subsystem, affecting NetworkManager and routing configuration operations, which aligns with ATT&CK technique T1547.001 for registry run keys and T1059.001 for command and scripting interpreter, as the system may attempt to recover from these failures through automated network management processes.
The resolution for CVE-2022-49592 involves correcting the mask calculation logic to properly handle queue numbers exceeding four, ensuring that left shift operations remain within the bounds of the 32-bit integer type. This fix requires careful validation of queue mapping parameters and implementation of proper bit masking techniques that prevent overflow conditions. System administrators should ensure their kernels are updated to versions containing this fix, particularly in embedded and IoT deployments where the affected kernel variants are commonly used. The mitigation strategy should include monitoring for UBSAN warnings in kernel logs and implementing proper kernel version management to prevent exploitation. Organizations using the stmmac driver with configurations that exceed four DMA queues should conduct thorough testing to validate the fix's effectiveness in their specific deployment environments, ensuring that network interface functionality remains stable under all expected operating conditions.