Linux Kernel up to 5.10.109/5.15.32/5.16.18/5.17.1 dma_mb state issue

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.10.109/5.15.32/5.16.18/5.17.1. It has been classified as problematic. This vulnerability affects the function dma_mb. This manipulation causes state issue. This vulnerability is handled as CVE-2022-49194. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.10.109/5.15.32/5.16.18/5.17.1. It has been declared as problematic. Affected by this vulnerability is the function dma_mb. The manipulation with an unknown input leads to a state issue vulnerability. The CWE definition for the vulnerability is CWE-371. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: net: bcmgenet: Use stronger register read/writes to assure ordering GCC12 appears to be much smarter about its dependency tracking and is aware that the relaxed variants are just normal loads and stores and this is causing problems like: [ 210.074549] ------------[ cut here ]------------ [ 210.079223] NETDEV WATCHDOG: enabcm6e4ei0 (bcmgenet): transmit queue 1 timed out [ 210.086717] WARNING: CPU: 1 PID: 0 at net/sched/sch_generic.c:529 dev_watchdog+0x234/0x240 [ 210.095044] Modules linked in: genet(E) nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat] [ 210.146561] ACPI CPPC: PCC check channel failed for ss: 0. ret=-110 [ 210.146927] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G E 5.17.0-rc7G12+ #58 [ 210.153226] CPPC Cpufreq:cppc_scale_freq_workfn: failed to read perf counters [ 210.161349] Hardware name: Raspberry Pi Foundation Raspberry Pi 4 Model B/Raspberry Pi 4 Model B, BIOS EDK2-DEV 02/08/2022 [ 210.161353] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 210.161358] pc : dev_watchdog+0x234/0x240 [ 210.161364] lr : dev_watchdog+0x234/0x240 [ 210.161368] sp : ffff8000080a3a40 [ 210.161370] x29: ffff8000080a3a40 x28: ffffcd425af87000 x27: ffff8000080a3b20 [ 210.205150] x26: ffffcd425aa00000 x25: 0000000000000001 x24: ffffcd425af8ec08 [ 210.212321] x23: 0000000000000100 x22: ffffcd425af87000 x21: ffff55b142688000 [ 210.219491] x20: 0000000000000001 x19: ffff55b1426884c8 x18: ffffffffffffffff [ 210.226661] x17: 64656d6974203120 x16: 0000000000000001 x15: 6d736e617274203a [ 210.233831] x14: 2974656e65676d63 x13: ffffcd4259c300d8 x12: ffffcd425b07d5f0 [ 210.241001] x11: 00000000ffffffff x10: ffffcd425b07d5f0 x9 : ffffcd4258bdad9c [ 210.248171] x8 : 00000000ffffdfff x7 : 000000000000003f x6 : 0000000000000000 [ 210.255341] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000001000 [ 210.262511] x2 : 0000000000001000 x1 : 0000000000000005 x0 : 0000000000000044 [ 210.269682] Call trace: [ 210.272133] dev_watchdog+0x234/0x240 [ 210.275811] call_timer_fn+0x3c/0x15c [ 210.279489] __run_timers.part.0+0x288/0x310 [ 210.283777] run_timer_softirq+0x48/0x80 [ 210.287716] __do_softirq+0x128/0x360 [ 210.291392] __irq_exit_rcu+0x138/0x140 [ 210.295243] irq_exit_rcu+0x1c/0x30 [ 210.298745] el1_interrupt+0x38/0x54 [ 210.302334] el1h_64_irq_handler+0x18/0x24 [ 210.306445] el1h_64_irq+0x7c/0x80 [ 210.309857] arch_cpu_idle+0x18/0x2c [ 210.313445] default_idle_call+0x4c/0x140 [ 210.317470] cpuidle_idle_call+0x14c/0x1a0 [ 210.321584] do_idle+0xb0/0x100 [ 210.324737] cpu_startup_entry+0x30/0x8c [ 210.328675] secondary_start_kernel+0xe4/0x110 [ 210.333138] __secondary_switched+0x94/0x98 The assumption when these were relaxed seems to be that device memory would be mapped non reordering, and that other constructs (spinlocks/etc) would provide the barriers to assure that packet data and in memory rings/queues were ordered with respect to device register reads/writes. This itself seems a bit sketchy, but the real problem with GCC12 is that it is moving the actual reads/writes around at will as though they were independent operations when in truth they are not, but the compiler can't know that. When looking at the assembly dumps for many of these routines its possible to see very clean, but not strictly in program order operations occurring as the compiler would be free to do if these weren't actually register reads/write operations. Its possible to suppress the timeout with a liberal bit of dma_mb()'s sprinkled around but the device still seems unable to reliably send/receive data. A better plan is to use the safer readl/writel everywhere. Since this partially reverts an older commit, which notes the use of the relaxed variants for performance reasons. I would suggest that any performance problems ---truncated---

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2022-49194 since 02/26/2025. The exploitation appears to be difficult. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/21/2025).

Upgrading to version 5.10.110, 5.15.33, 5.16.19 or 5.17.2 eliminates this vulnerability. Applying the patch b26091a02093104259ca64aeca73601e56160d62/06d836801cd82ded282aaf9e888ff9e7e4a88b91/1d717816189fd68f9e089cf89ed1f7327d2c2e71/f49769b462f282477ca801cf648f875b1c5b59db/8d3ea3d402db94b61075617e71b67459a714a502 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.109
• 5.15.0
• 5.15.1
• 5.15.2
• 5.15.3
• 5.15.4
• 5.15.5
• 5.15.6
• 5.15.7
• 5.15.8
• 5.15.9
• 5.15.10
• 5.15.11
• 5.15.12
• 5.15.13
• 5.15.14
• 5.15.15
• 5.15.16
• 5.15.17
• 5.15.18
• 5.15.19
• 5.15.20
• 5.15.21
• 5.15.22
• 5.15.23
• 5.15.24
• 5.15.25
• 5.15.26
• 5.15.27
• 5.15.28
• 5.15.29
• 5.15.30
• 5.15.31
• 5.15.32
• 5.16.0
• 5.16.1
• 5.16.2
• 5.16.3
• 5.16.4
• 5.16.5
• 5.16.6
• 5.16.7
• 5.16.8
• 5.16.9
• 5.16.10
• 5.16.11
• 5.16.12
• 5.16.13
• 5.16.14
• 5.16.15
• 5.16.16
• 5.16.17
• 5.16.18
• 5.17.0
• 5.17.1

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

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