CVE-2026-98922

In the Linux kernel, the following vulnerability has been resolved:

net: emac: move setting of netops to fix crash

fixes the following crash on driver initialization:

|BUG: Kernel NULL pointer dereference on read at 0x00000158 |Faulting instruction address: 0xc0566b40 |Oops: Kernel access of bad area, sig: 11 [#1] |BE PAGE SIZE=4K PowerPC 44x Platform |Modules linked in: |CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: GW 7.3.0-rc3+ #1 |Tainted: [W]=WARN |Hardware name: MyBook Live APM821XX 0x12c41c83 PowerPC 44x Platform |NIP: c0566b40 LR: c05648f8 CTR: c04c1e9c |REGS: c1053a20 TRAP: 0300 Tainted: GW (7.3.0-rc3+) |MSR: 0002b000 <CE,EE,FP,ME> CR: 24008808 XER: 00000000 |DEAR: 00000158 ESR: 00000000 |GPR00: c05648f8 c1053b10 c1063600 c1030000 c5ab3000 00000000 [...] |GPR08: 00000002 00000000 00000000 c1053b40 84002808 00000000 [...] |GPR16: cfffd210 00000002 c0beafcc cfffc960 00000000 c1030644 [...] |GPR24: c0beafbc c1037000 00000000 0000000a 00000000 c1030000 [...] |NIP [c0566b40] phy link topo add phy+0x2c/0x1d0 |LR [c05648f8] phy attach direct+0x1a4/0x368 |Call Trace: |[c1053b10] [c0811e04] klist put+0x54/0xb4 (unreliable) |[c1053b40] [c05648f8] phy attach direct+0x1a4/0x368 |[c1053b70] [c0564ae8] phy connect direct+0x2c/0x60 |[c1053b90] [c056c7a8] of phy connect+0x50/0x74 |[c1053bc0] [c0572a88] emac probe+0xd50/0x119c |[c1053c90] [c04cb770] platform probe+0x74/0xa4 |[c1053cb0] [c04c8f08] really probe+0x120/0x2b0 |[c1053cd0] [c04c9254] driver probe device+0x1bc/0x1fc |[c1053d00] [c04c9334] driver probe device+0x38/0xa8 |[c1053d30] [c04c9560] driver attach+0xf4/0x10c |[c1053d50] [c04c6af8] bus for each dev+0x68/0xd0 |[c1053d90] [c04c7c34] bus add driver+0xcc/0x1ec |[c1053dc0] [c04c9f6c] driver register+0xcc/0x110 |[c1053de0] [c0aa3f40] emac init+0x1c4/0x200

This bug showed up starting with v7.3-rc1. At the NIP in phy link topo add phy() is a netdev need ops lock() check. This was added by the following commit ded86da4bbb7 ("net: ethtool: relax ethnl req get phydev() locking assertion")

The bug shows up because at the time of phy connect() was called, the netdev ops were not yet determined. My fix is to move the code that sets netdev ops+commac.ops+ethtool ops further up as emac init config() derives that by looking at the device-tree and sets the required dev->phy mode accordingly.

During review, the Sashiko bot's AI stated that the commac assignment became a dead store. Great catch! To keep the original behavior as-is, one mentioned option "set dev->commac.ops = &emac commac ops only in the non-gige case?" sounded like a great plan. So the dev->commac.ops assignment for the non-gige-case moves into the else block.

This patch was tested on a WD MyBook Live (RGMII). the device now works again.