CVE-2022-49847

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

net: ethernet: ti: am65-cpsw: Fix segmentation fault at module unload

Move am65_cpsw_nuss_phylink_cleanup() call to after am65_cpsw_nuss_cleanup_ndev() so phylink is still valid to prevent the below Segmentation fault on module remove when first slave link is up.

[ 31.652944] Unable to handle kernel paging request at virtual address 00040008000005f4 [ 31.684627] Mem abort info: [ 31.687446] ESR = 0x0000000096000004 [ 31.704614] EC = 0x25: DABT (current EL), IL = 32 bits [ 31.720663] SET = 0, FnV = 0 [ 31.723729] EA = 0, S1PTW = 0 [ 31.740617] FSC = 0x04: level 0 translation fault [ 31.756624] Data abort info: [ 31.759508] ISV = 0, ISS = 0x00000004 [ 31.776705] CM = 0, WnR = 0 [ 31.779695] [00040008000005f4] address between user and kernel address ranges [ 31.808644] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP [ 31.814928] Modules linked in: wlcore_sdio wl18xx wlcore mac80211 libarc4 cfg80211 rfkill crct10dif_ce phy_gmii_sel ti_am65_cpsw_nuss(-) sch_fq_codel ipv6 [ 31.828776] CPU: 0 PID: 1026 Comm: modprobe Not tainted 6.1.0-rc2-00012-gfabfcf7dafdb-dirty #160 [ 31.837547] Hardware name: Texas Instruments AM625 (DT) [ 31.842760] pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 31.849709] pc : phy_stop+0x18/0xf8 [ 31.853202] lr : phylink_stop+0x38/0xf8 [ 31.857031] sp : ffff80000a0839f0 [ 31.860335] x29: ffff80000a0839f0 x28: ffff000000de1c80 x27: 0000000000000000 [ 31.867462] x26: 0000000000000000 x25: 0000000000000000 x24: ffff80000a083b98 [ 31.874589] x23: 0000000000000800 x22: 0000000000000001 x21: ffff000001bfba90 [ 31.881715] x20: ffff0000015ee000 x19: 0004000800000200 x18: 0000000000000000 [ 31.888842] x17: ffff800076c45000 x16: ffff800008004000 x15: 000058e39660b106 [ 31.895969] x14: 0000000000000144 x13: 0000000000000144 x12: 0000000000000000 [ 31.903095] x11: 000000000000275f x10: 00000000000009e0 x9 : ffff80000a0837d0 [ 31.910222] x8 : ffff000000de26c0 x7 : ffff00007fbd6540 x6 : ffff00007fbd64c0 [ 31.917349] x5 : ffff00007fbd0b10 x4 : ffff00007fbd0b10 x3 : ffff00007fbd3920 [ 31.924476] x2 : d0a07fcff8b8d500 x1 : 0000000000000000 x0 : 0004000800000200 [ 31.931603] Call trace: [ 31.934042] phy_stop+0x18/0xf8 [ 31.937177] phylink_stop+0x38/0xf8 [ 31.940657] am65_cpsw_nuss_ndo_slave_stop+0x28/0x1e0 [ti_am65_cpsw_nuss] [ 31.947452] __dev_close_many+0xa4/0x140 [ 31.951371] dev_close_many+0x84/0x128 [ 31.955115] unregister_netdevice_many+0x130/0x6d0 [ 31.959897] unregister_netdevice_queue+0x94/0xd8 [ 31.964591] unregister_netdev+0x24/0x38 [ 31.968504] am65_cpsw_nuss_cleanup_ndev.isra.0+0x48/0x70 [ti_am65_cpsw_nuss] [ 31.975637] am65_cpsw_nuss_remove+0x58/0xf8 [ti_am65_cpsw_nuss]

This patch fixes a segmentation fault that occurred when unloading the ti_am65_cpsw_nuss module if the PHY link was still active. The issue stemmed from calling am65_cpsw_nuss_phylink_cleanup() too early, which invalidated the phylink structure before it was used in the network device cleanup routine. The fix moves the cleanup call to after am65_cpsw_nuss_cleanup_ndev() to maintain correct resource ordering. Without this fix, unloading the driver under certain runtime conditions (e.g., active link) would lead to a kernel oops and possible system instability due to invalid memory access.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.